diff --git a/api/JSONDataFormatter.php b/api/JSONDataFormatter.php
index 6f13222b0..295d60cee 100644
--- a/api/JSONDataFormatter.php
+++ b/api/JSONDataFormatter.php
@@ -62,7 +62,7 @@ class JSONDataFormatter extends DataFormatter {
 		}
 
 		if($this->relationDepth > 0) {
-			foreach($obj->has_one() as $relName => $relClass) {
+			foreach($obj->hasOne() as $relName => $relClass) {
 				if(!singleton($relClass)->stat('api_access')) continue;
 
 				// Field filtering
@@ -82,7 +82,7 @@ class JSONDataFormatter extends DataFormatter {
 				));
 			}
 
-			foreach($obj->has_many() as $relName => $relClass) {
+			foreach($obj->hasMany() as $relName => $relClass) {
 				if(!singleton($relClass)->stat('api_access')) continue;
 
 				// Field filtering
@@ -103,7 +103,7 @@ class JSONDataFormatter extends DataFormatter {
 				$serobj->$relName = $innerParts;
 			}
 
-			foreach($obj->many_many() as $relName => $relClass) {
+			foreach($obj->manyMany() as $relName => $relClass) {
 				if(!singleton($relClass)->stat('api_access')) continue;
 
 				// Field filtering
diff --git a/api/XMLDataFormatter.php b/api/XMLDataFormatter.php
index d76ec68c0..2cb848639 100644
--- a/api/XMLDataFormatter.php
+++ b/api/XMLDataFormatter.php
@@ -68,7 +68,7 @@ class XMLDataFormatter extends DataFormatter {
 		}
 
 		if($this->relationDepth > 0) {
-			foreach($obj->has_one() as $relName => $relClass) {
+			foreach($obj->hasOne() as $relName => $relClass) {
 				if(!singleton($relClass)->stat('api_access')) continue;
 
 				// Field filtering
@@ -85,7 +85,7 @@ class XMLDataFormatter extends DataFormatter {
 					. "\"></$relName>\n";
 			}
 
-			foreach($obj->has_many() as $relName => $relClass) {
+			foreach($obj->hasMany() as $relName => $relClass) {
 				if(!singleton($relClass)->stat('api_access')) continue;
 
 				// Field filtering
@@ -103,7 +103,7 @@ class XMLDataFormatter extends DataFormatter {
 				$xml .= "</$relName>\n";
 			}
 
-			foreach($obj->many_many() as $relName => $relClass) {
+			foreach($obj->manyMany() as $relName => $relClass) {
 				if(!singleton($relClass)->stat('api_access')) continue;
 
 				// Field filtering
diff --git a/dev/BulkLoader.php b/dev/BulkLoader.php
index ac0333f08..53651cc34 100644
--- a/dev/BulkLoader.php
+++ b/dev/BulkLoader.php
@@ -220,9 +220,9 @@ abstract class BulkLoader extends ViewableData {
 		// using $$includerelations flag as false, so that it only contain $db fields
 		$spec['fields'] = (array)singleton($this->objectClass)->fieldLabels(false);
 
-		$has_ones = singleton($this->objectClass)->has_one();
-		$has_manys = singleton($this->objectClass)->has_many();
-		$many_manys = singleton($this->objectClass)->many_many();
+		$has_ones = singleton($this->objectClass)->hasOne();
+		$has_manys = singleton($this->objectClass)->hasMany();
+		$many_manys = singleton($this->objectClass)->manyMany();
 
 		$spec['relations'] = (array)$has_ones + (array)$has_manys + (array)$many_manys;
 
diff --git a/dev/CsvBulkLoader.php b/dev/CsvBulkLoader.php
index fed49f334..4d6fea561 100644
--- a/dev/CsvBulkLoader.php
+++ b/dev/CsvBulkLoader.php
@@ -120,7 +120,7 @@ class CsvBulkLoader extends BulkLoader {
 					$relationObj = $obj->{$this->relationCallbacks[$fieldName]['callback']}($val, $record);
 				}
 				if(!$relationObj || !$relationObj->exists()) {
-					$relationClass = $obj->has_one($relationName);
+					$relationClass = $obj->hasOneComponent($relationName);
 					$relationObj = new $relationClass();
 					//write if we aren't previewing
 					if (!$preview) $relationObj->write();
diff --git a/dev/FixtureBlueprint.php b/dev/FixtureBlueprint.php
index b1e79a5d9..388c273a4 100644
--- a/dev/FixtureBlueprint.php
+++ b/dev/FixtureBlueprint.php
@@ -110,7 +110,11 @@ class FixtureBlueprint {
 			// Populate overrides
 			if($data) foreach($data as $fieldName => $fieldVal) {
 				// Defer relationship processing
-				if($obj->many_many($fieldName) || $obj->has_many($fieldName) || $obj->has_one($fieldName)) {
+				if(
+					$obj->manyManyComponent($fieldName)
+					|| $obj->hasManyComponent($fieldName)
+					|| $obj->hasOneComponent($fieldName)
+				) {
 					continue;
 				}
 
@@ -127,7 +131,7 @@ class FixtureBlueprint {
 
 			// Populate all relations
 			if($data) foreach($data as $fieldName => $fieldVal) {
-				if($obj->many_many($fieldName) || $obj->has_many($fieldName)) {
+				if($obj->manyManyComponent($fieldName) || $obj->hasManyComponent($fieldName)) {
 					$obj->write();
 
 					$parsedItems = array();
@@ -165,15 +169,15 @@ class FixtureBlueprint {
 							$parsedItems[] = $this->parseValue($item, $fixtures);
 						}
 
-						if($obj->has_many($fieldName)) {
+						if($obj->hasManyComponent($fieldName)) {
 							$obj->getComponents($fieldName)->setByIDList($parsedItems);
-						} elseif($obj->many_many($fieldName)) {
+						} elseif($obj->manyManyComponent($fieldName)) {
 							$obj->getManyManyComponents($fieldName)->setByIDList($parsedItems);
 						}
 					}
 				} else {
 					$hasOneField = preg_replace('/ID$/', '', $fieldName);
-					if($className = $obj->has_one($hasOneField)) {
+					if($className = $obj->hasOneComponent($hasOneField)) {
 						$obj->{$hasOneField.'ID'} = $this->parseValue($fieldVal, $fixtures, $fieldClass);
 						// Inject class for polymorphic relation
 						if($className === 'DataObject') {
diff --git a/docs/en/02_Developer_Guides/00_Model/02_Relations.md b/docs/en/02_Developer_Guides/00_Model/02_Relations.md
index e07ec169b..73d50d9f9 100644
--- a/docs/en/02_Developer_Guides/00_Model/02_Relations.md
+++ b/docs/en/02_Developer_Guides/00_Model/02_Relations.md
@@ -204,6 +204,27 @@ The relationship can also be navigated in [templates](../templates).
 		<% end_if %>
 	<% end_with %>
 
+To specify multiple $many_manys between the same classes, use the dot notation to distinguish them like below:
+
+	:::php
+	<?php
+
+	class Category extends DataObject {
+		
+		private static $many_many = array(
+			'Products' => 'Product',
+			'FeaturedProducts' => 'Product'
+		);
+	}
+
+	class Product extends DataObject {
+		
+		private static $belongs_many_many = array(
+			'Categories' => 'Category.Products',
+			'FeaturedInCategories' => 'Category.FeaturedProducts'
+		);
+	}
+
 ## many_many or belongs_many_many?
 
 If you're unsure about whether an object should take on `many_many` or `belongs_many_many`, the best way to think about it is that the object where the relationship will be edited (i.e. via checkboxes) should contain the `many_many`. For instance, in a `many_many` of Product => Categories, the `Product` should contain the `many_many`, because it is much more likely that the user will select Categories for a Product than vice-versa.
diff --git a/forms/FileField.php b/forms/FileField.php
index 52d425790..b52ef5960 100644
--- a/forms/FileField.php
+++ b/forms/FileField.php
@@ -109,7 +109,7 @@ class FileField extends FormField {
 
 		if($this->relationAutoSetting) {
 			// assume that the file is connected via a has-one
-			$hasOnes = $record->has_one($this->name);
+			$hasOnes = $record->hasOne($this->name);
 			// try to create a file matching the relation
 			$file = (is_string($hasOnes)) ? Object::create($hasOnes) : new $fileClass();
 		} else if($record instanceof File) {
diff --git a/forms/FormScaffolder.php b/forms/FormScaffolder.php
index 563ad9b15..1fa632315 100644
--- a/forms/FormScaffolder.php
+++ b/forms/FormScaffolder.php
@@ -93,8 +93,8 @@ class FormScaffolder extends Object {
 		}
 
 		// add has_one relation fields
-		if($this->obj->has_one()) {
-			foreach($this->obj->has_one() as $relationship => $component) {
+		if($this->obj->hasOne()) {
+			foreach($this->obj->hasOne() as $relationship => $component) {
 				if($this->restrictFields && !in_array($relationship, $this->restrictFields)) continue;
 				$fieldName = $component === 'DataObject'
 					? $relationship // Polymorphic has_one field is composite, so don't refer to ID subfield
@@ -118,10 +118,10 @@ class FormScaffolder extends Object {
 		// only add relational fields if an ID is present
 		if($this->obj->ID) {
 			// add has_many relation fields
-			if($this->obj->has_many()
+			if($this->obj->hasMany()
 					&& ($this->includeRelations === true || isset($this->includeRelations['has_many']))) {
 
-				foreach($this->obj->has_many() as $relationship => $component) {
+				foreach($this->obj->hasMany() as $relationship => $component) {
 					if($this->tabbed) {
 						$relationTab = $fields->findOrMakeTab(
 							"Root.$relationship",
@@ -145,10 +145,10 @@ class FormScaffolder extends Object {
 				}
 			}
 
-			if($this->obj->many_many()
+			if($this->obj->manyMany()
 					&& ($this->includeRelations === true || isset($this->includeRelations['many_many']))) {
 
-				foreach($this->obj->many_many() as $relationship => $component) {
+				foreach($this->obj->manyMany() as $relationship => $component) {
 					if($this->tabbed) {
 						$relationTab = $fields->findOrMakeTab(
 							"Root.$relationship",
diff --git a/forms/UploadField.php b/forms/UploadField.php
index 3e6dc2ecc..d76da42d8 100644
--- a/forms/UploadField.php
+++ b/forms/UploadField.php
@@ -502,7 +502,7 @@ class UploadField extends FileField {
 		if($relation && ($relation instanceof RelationList || $relation instanceof UnsavedRelationList)) {
 			// has_many or many_many
 			$relation->setByIDList($idList);
-		} elseif($record->has_one($fieldname)) {
+		} elseif($record->hasOneComponent($fieldname)) {
 			// has_one
 			$record->{"{$fieldname}ID"} = $idList ? reset($idList) : 0;
 		}
@@ -590,7 +590,7 @@ class UploadField extends FileField {
 		if(empty($allowedMaxFileNumber)) {
 			$record = $this->getRecord();
 			$name = $this->getName();
-			if($record && $record->has_one($name)) {
+			if($record && $record->hasOneComponent($name)) {
 				return 1; // Default for has_one
 			} else {
 				return null; // Default for has_many and many_many
diff --git a/model/DataDifferencer.php b/model/DataDifferencer.php
index f1771f41f..e7c3ed38a 100644
--- a/model/DataDifferencer.php
+++ b/model/DataDifferencer.php
@@ -78,7 +78,7 @@ class DataDifferencer extends ViewableData {
 			$fields = array_keys($this->toRecord->toMap());
 		}
 
-		$hasOnes = array_merge($this->fromRecord->has_one(), $this->toRecord->has_one());
+		$hasOnes = array_merge($this->fromRecord->hasOne(), $this->toRecord->hasOne());
 
 		// Loop through properties
 		foreach($fields as $field) {
diff --git a/model/DataObject.php b/model/DataObject.php
index 37d114ffd..f1ffa71a2 100644
--- a/model/DataObject.php
+++ b/model/DataObject.php
@@ -547,10 +547,10 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 		// DO NOT copy has_many relations, because copying the relation would result in us changing the has_one
 		// relation on the other side of this relation to point at the copy and no longer the original (being a
 		// has_one, it can only point at one thing at a time). So, all relations except has_many can and are copied
-		if ($sourceObject->has_one()) foreach($sourceObject->has_one() as $name => $type) {
+		if ($sourceObject->hasOne()) foreach($sourceObject->hasOne() as $name => $type) {
 			$this->duplicateRelations($sourceObject, $destinationObject, $name);
 		}
-		if ($sourceObject->many_many()) foreach($sourceObject->many_many() as $name => $type) {
+		if ($sourceObject->manyMany()) foreach($sourceObject->manyMany() as $name => $type) {
 			//many_many include belongs_many_many
 			$this->duplicateRelations($sourceObject, $destinationObject, $name);
 		}
@@ -666,24 +666,24 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 		if($this->class == 'DataObject') return;
 
 		// Set up accessors for joined items
-		if($manyMany = $this->many_many()) {
+		if($manyMany = $this->manyMany()) {
 			foreach($manyMany as $relationship => $class) {
 				$this->addWrapperMethod($relationship, 'getManyManyComponents');
 			}
 		}
-		if($hasMany = $this->has_many()) {
+		if($hasMany = $this->hasMany()) {
 
 			foreach($hasMany as $relationship => $class) {
 				$this->addWrapperMethod($relationship, 'getComponents');
 			}
 
 		}
-		if($hasOne = $this->has_one()) {
+		if($hasOne = $this->hasOne()) {
 			foreach($hasOne as $relationship => $class) {
 				$this->addWrapperMethod($relationship, 'getComponent');
 			}
 		}
-		if($belongsTo = $this->belongs_to()) foreach(array_keys($belongsTo) as $relationship) {
+		if($belongsTo = $this->belongsTo()) foreach(array_keys($belongsTo) as $relationship) {
 			$this->addWrapperMethod($relationship, 'getComponent');
 		}
 	}
@@ -972,7 +972,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 
 		// merge relations
 		if($includeRelations) {
-			if($manyMany = $this->many_many()) {
+			if($manyMany = $this->manyMany()) {
 				foreach($manyMany as $relationship => $class) {
 					$leftComponents = $leftObj->getManyManyComponents($relationship);
 					$rightComponents = $rightObj->getManyManyComponents($relationship);
@@ -983,7 +983,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 				}
 			}
 
-			if($hasMany = $this->has_many()) {
+			if($hasMany = $this->hasMany()) {
 				foreach($hasMany as $relationship => $class) {
 					$leftComponents = $leftObj->getComponents($relationship);
 					$rightComponents = $rightObj->getComponents($relationship);
@@ -995,7 +995,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 
 			}
 
-			if($hasOne = $this->has_one()) {
+			if($hasOne = $this->hasOne()) {
 				foreach($hasOne as $relationship => $class) {
 					$leftComponent = $leftObj->getComponent($relationship);
 					$rightComponent = $rightObj->getComponent($relationship);
@@ -1130,7 +1130,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 					$this->$fieldName = $fieldValue;
 				}
 				// Set many-many defaults with an array of ids
-				if(is_array($fieldValue) && $this->many_many($fieldName)) {
+				if(is_array($fieldValue) && $this->manyManyComponent($fieldName)) {
 					$manyManyJoin = $this->$fieldName();
 					$manyManyJoin->setByIdList($fieldValue);
 				}
@@ -1497,7 +1497,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 			return $this->components[$componentName];
 		}
 
-		if($class = $this->has_one($componentName)) {
+		if($class = $this->hasOneComponent($componentName)) {
 			$joinField = $componentName . 'ID';
 			$joinID    = $this->getField($joinField);
 
@@ -1514,7 +1514,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 			if(empty($component)) {
 				$component = $this->model->$class->newObject();
 			}
-		} elseif($class = $this->belongs_to($componentName)) {
+		} elseif($class = $this->belongsToComponent($componentName)) {
 
 			$joinField = $this->getRemoteJoinField($componentName, 'belongs_to', $polymorphic);
 			$joinID    = $this->ID;
@@ -1553,18 +1553,18 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 * Returns a one-to-many relation as a HasManyList
 	 *
 	 * @param string $componentName Name of the component
-	 * @param string $filter A filter to be inserted into the WHERE clause
-	 * @param string|array $sort A sort expression to be inserted into the ORDER BY clause. If omitted, the static
-	 *                           field $default_sort on the component class will be used.
+	 * @param string|null $filter Deprecated. A filter to be inserted into the WHERE clause
+	 * @param string|null|array $sort Deprecated. A sort expression to be inserted into the ORDER BY clause. If omitted,
+	 *                                the static field $default_sort on the component class will be used.
 	 * @param string $join Deprecated, use leftJoin($table, $joinClause) instead
-	 * @param string|array $limit A limit expression to be inserted into the LIMIT clause
+	 * @param string|null|array $limit Deprecated. A limit expression to be inserted into the LIMIT clause
 	 *
 	 * @return HasManyList The components of the one-to-many relationship.
 	 */
-	public function getComponents($componentName, $filter = "", $sort = "", $join = "", $limit = null) {
+	public function getComponents($componentName, $filter = null, $sort = null, $join = null, $limit = null) {
 		$result = null;
 
-		if(!$componentClass = $this->has_many($componentName)) {
+		if(!$componentClass = $this->hasManyComponent($componentName)) {
 			user_error("DataObject::getComponents(): Unknown 1-to-many component '$componentName'"
 				. " on class '$this->class'", E_USER_ERROR);
 		}
@@ -1575,6 +1575,11 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 			);
 		}
 
+		if($filter !== null || $sort !== null || $limit !== null) {
+			Deprecation::notice('3.2', 'The $filter, $sort and $limit parameters for DataObject::getComponents() 
+				have been deprecated. Please manipluate the returned list directly.', Deprecation::SCOPE_GLOBAL);
+		}
+
 		// If we haven't been written yet, we can't save these relations, so use a list that handles this case
 		if(!$this->ID) {
 			if(!isset($this->unsavedRelations[$componentName])) {
@@ -1647,7 +1652,12 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 */
 	public function getRemoteJoinField($component, $type = 'has_many', &$polymorphic = false) {
 		// Extract relation from current object
-		$remoteClass = $this->$type($component, false);
+		if($type === 'has_many') {
+			$remoteClass = $this->hasManyComponent($component, false);
+		} else {
+			$remoteClass = $this->belongsToComponent($component, false);
+		}		
+		
 		if(empty($remoteClass)) {
 			throw new Exception("Unknown $type component '$component' on class '$this->class'");
 		}
@@ -1716,8 +1726,15 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 *
 	 * @todo Implement query-params
 	 */
-	public function getManyManyComponents($componentName, $filter = "", $sort = "", $join = "", $limit = "") {
-		list($parentClass, $componentClass, $parentField, $componentField, $table) = $this->many_many($componentName);
+	public function getManyManyComponents($componentName, $filter = null, $sort = null, $join = null, $limit = null) {
+		list($parentClass, $componentClass, $parentField, $componentField, $table)
+			= $this->manyManyComponent($componentName);
+
+		if($filter !== null || $sort !== null || $join !== null || $limit !== null) {
+			Deprecation::notice('3.2', 'The $filter, $sort, $join and $limit parameters for 
+				DataObject::getManyManyComponents() have been deprecated. 
+				Please manipluate the returned list directly.', Deprecation::SCOPE_GLOBAL);
+		}
 
 		// If we haven't been written yet, we can't save these relations, so use a list that handles this case
 		if(!$this->ID) {
@@ -1730,7 +1747,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 
 		$result = ManyManyList::create(
 			$componentClass, $table, $componentField, $parentField,
-			$this->many_many_extraFields($componentName)
+			$this->manyManyExtraFieldsForComponent($componentName)
 		);
 		if($this->model) $result->setDataModel($this->model);
 
@@ -1743,64 +1760,91 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 			->limit($limit);
 	}
 
+	/**
+	 * @deprecated 4.0 Method has been replaced by hasOne() and hasOneComponent()
+	 * @param string $component
+	 * @return array|null
+	 */
+	public function has_one($component = null) {
+		if($component) {
+			Deprecation::notice('3.2', 'Please use hasOneComponent() instead');
+			return $this->hasOneComponent($component);
+		}
+
+		Deprecation::notice('3.2', 'Please use hasOne() instead');
+		return $this->hasOne();
+	}
+
 	/**
 	 * Return the class of a one-to-one component.  If $component is null, return all of the one-to-one components and
 	 * their classes. If the selected has_one is a polymorphic field then 'DataObject' will be returned for the type.
 	 *
-	 * @param string $component Name of component
-	 *
-	 * @return string|array The class of the one-to-one component, or an array of all one-to-one components and their
-	 *                      classes.
+	 * @param string $component Deprecated - Name of component
+	 * @return string|array The class of the one-to-one component, or an array of all one-to-one components and
+	 * 							their classes.
 	 */
-	public function has_one($component = null) {
-		$classes = ClassInfo::ancestry($this);
-
-		foreach($classes as $class) {
-			// Wait until after we reach DataObject
-			if(in_array($class, array('Object', 'ViewableData', 'DataObject'))) continue;
-
-			if($component) {
-				$hasOne = Config::inst()->get($class, 'has_one', Config::UNINHERITED);
-
-				if(isset($hasOne[$component])) {
-					return $hasOne[$component];
-				}
-			} else {
-				$newItems = (array)Config::inst()->get($class, 'has_one', Config::UNINHERITED);
-				// Validate the data
-				foreach($newItems as $k => $v) {
-					if(!is_string($k) || is_numeric($k) || !is_string($v)) {
-						user_error("$class::\$has_one has a bad entry: "
-						. var_export($k,true). " => " . var_export($v,true) . ".  Each map key should be a"
-						. " relationship name, and the map value should be the data class to join to.", E_USER_ERROR);
-					}
-				}
-				$items = isset($items) ? array_merge($newItems, (array)$items) : $newItems;
-			}
+	public function hasOne($component = null) {
+		if($component) {
+			Deprecation::notice(
+				'3.2',
+				'Please use DataObject::hasOneComponent() instead of passing a component name to hasOne()',
+				Deprecation::SCOPE_GLOBAL
+			);
+			return $this->hasOneComponent($component);
 		}
-		return isset($items) ? $items : null;
+
+		return (array)Config::inst()->get($this->class, 'has_one', Config::INHERITED);
+	}
+
+	/**
+	 * Return data for a specific has_one component.
+	 * @param string $component
+	 * @return string|null
+	 */
+	public function hasOneComponent($component) {
+		$hasOnes = (array)Config::inst()->get($this->class, 'has_one', Config::INHERITED);
+
+		if(isset($hasOnes[$component])) {
+			return $hasOnes[$component];
+		}
+	}
+
+	/**
+	 * @deprecated 4.0 Method has been replaced by belongsTo() and belongsToComponent()
+	 * @param string $component
+	 * @param bool $classOnly
+	 * @return array|null
+	 */
+	public function belongs_to($component = null, $classOnly = true) {
+		if($component) {
+			Deprecation::notice('3.2', 'Please use belongsToComponent() instead');
+			return $this->belongsToComponent($component, $classOnly);
+		}
+
+		Deprecation::notice('3.2', 'Please use belongsTo() instead');
+		return $this->belongsTo(null, $classOnly);
 	}
 
 	/**
 	 * Returns the class of a remote belongs_to relationship. If no component is specified a map of all components and
 	 * their class name will be returned.
 	 *
-	 * @param string $component
+	 * @param string $component - Name of component
 	 * @param bool $classOnly If this is TRUE, than any has_many relationships in the form "ClassName.Field" will have
 	 *        the field data stripped off. It defaults to TRUE.
 	 * @return string|array
 	 */
-	public function belongs_to($component = null, $classOnly = true) {
-		$belongsTo = $this->config()->belongs_to;
-
+	public function belongsTo($component = null, $classOnly = true) {
 		if($component) {
-			if($belongsTo && array_key_exists($component, $belongsTo)) {
-				$belongsTo = $belongsTo[$component];
-			} else {
-				return false;
-			}
+			Deprecation::notice(
+				'3.2',
+				'Please use DataObject::belongsToComponent() instead of passing a component name to belongsTo()',
+				Deprecation::SCOPE_GLOBAL
+			);
+			return $this->belongsToComponent($component, $classOnly);
 		}
 
+		$belongsTo = (array)Config::inst()->get($this->class, 'belongs_to', Config::INHERITED);
 		if($belongsTo && $classOnly) {
 			return preg_replace('/(.+)?\..+/', '$1', $belongsTo);
 		} else {
@@ -1808,9 +1852,28 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 		}
 	}
 
+	/**
+	 * Return data for a specific belongs_to component.
+	 * @param string $component
+	 * @param bool $classOnly If this is TRUE, than any has_many relationships in the form "ClassName.Field" will have
+	 *        the field data stripped off. It defaults to TRUE.
+	 * @return string|false
+	 */
+	public function belongsToComponent($component, $classOnly = true) {
+		$belongsTo = (array)Config::inst()->get($this->class, 'belongs_to', Config::INHERITED);
+
+		if($belongsTo && array_key_exists($component, $belongsTo)) {
+			$belongsTo = $belongsTo[$component];
+		} else {
+			return false;
+		}
+
+		return ($classOnly) ? preg_replace('/(.+)?\..+/', '$1', $belongsTo) : $belongsTo;
+	}
+
 	/**
 	 * Return all of the database fields defined in self::$db and all the parent classes.
-	 * Doesn't include any fields specified by self::$has_one.  Use $this->has_one() to get these fields
+	 * Doesn't include any fields specified by self::$has_one.  Use $this->hasOne() to get these fields
 	 *
 	 * @param string $fieldName Limit the output to a specific field name
 	 * @return array The database fields
@@ -1837,15 +1900,6 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 					return $dbItems[$fieldName];
 				}
 			} else {
-				// Validate the data
-				foreach($dbItems as $k => $v) {
-					if(!is_string($k) || is_numeric($k) || !is_string($v)) {
-						user_error("$class::\$db has a bad entry: "
-						. var_export($k,true). " => " . var_export($v,true) . ".  Each map key should be a"
-						. " property name, and the map value should be the property type.", E_USER_ERROR);
-					}
-				}
-
 				$items = isset($items) ? array_merge((array) $items, $dbItems) : $dbItems;
 			}
 		}
@@ -1853,26 +1907,42 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 		return $items;
 	}
 
+	/**
+	 * @deprecated 4.0 Method has been replaced by hasMany() and hasManyComponent()
+	 * @param string $component
+	 * @param bool $classOnly
+	 * @return array|null
+	 */
+	public function has_many($component = null, $classOnly = true) {
+		if($component) {
+			Deprecation::notice('3.2', 'Please use hasManyComponent() instead');
+			return $this->hasManyComponent($component, $classOnly);
+		}
+
+		Deprecation::notice('3.2', 'Please use hasMany() instead');
+		return $this->hasMany(null, $classOnly);
+	}
+
 	/**
 	 * Gets the class of a one-to-many relationship. If no $component is specified then an array of all the one-to-many
 	 * relationships and their classes will be returned.
 	 *
-	 * @param string $component Name of component
+	 * @param string $component Deprecated - Name of component
 	 * @param bool $classOnly If this is TRUE, than any has_many relationships in the form "ClassName.Field" will have
 	 *        the field data stripped off. It defaults to TRUE.
-	 * @return string|array
+	 * @return string|array|false
 	 */
-	public function has_many($component = null, $classOnly = true) {
-		$hasMany = $this->config()->has_many;
-
+	public function hasMany($component = null, $classOnly = true) {
 		if($component) {
-			if($hasMany && array_key_exists($component, $hasMany)) {
-				$hasMany = $hasMany[$component];
-			} else {
-				return false;
-			}
+			Deprecation::notice(
+				'3.2',
+				'Please use DataObject::hasManyComponent() instead of passing a component name to hasMany()',
+				Deprecation::SCOPE_GLOBAL
+			);
+			return $this->hasManyComponent($component, $classOnly);
 		}
 
+		$hasMany = (array)Config::inst()->get($this->class, 'has_many', Config::INHERITED);
 		if($hasMany && $classOnly) {
 			return preg_replace('/(.+)?\..+/', '$1', $hasMany);
 		} else {
@@ -1880,170 +1950,217 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 		}
 	}
 
+	/**
+	 * Return data for a specific has_many component.
+	 * @param string $component
+	 * @param bool $classOnly If this is TRUE, than any has_many relationships in the form "ClassName.Field" will have
+	 *        the field data stripped off. It defaults to TRUE.
+	 * @return string|false
+	 */
+	public function hasManyComponent($component, $classOnly = true) {
+		$hasMany = (array)Config::inst()->get($this->class, 'has_many', Config::INHERITED);
+
+		if($hasMany && array_key_exists($component, $hasMany)) {
+			$hasMany = $hasMany[$component];
+		} else {
+			return false;
+		}
+
+		return ($classOnly) ? preg_replace('/(.+)?\..+/', '$1', $hasMany) : $hasMany;
+	}
+
+	/**
+	 * @deprecated 4.0 Method has been replaced by manyManyExtraFields() and
+	 *                 manyManyExtraFieldsForComponent()
+	 * @param string $component
+	 * @return array
+	 */
+	public function many_many_extraFields($component = null) {
+		if($component) {
+			Deprecation::notice('3.2', 'Please use manyManyExtraFieldsForComponent() instead');
+			return $this->manyManyExtraFieldsForComponent($component);
+		}
+
+		Deprecation::notice('3.2', 'Please use manyManyExtraFields() instead');
+		return $this->manyManyExtraFields();
+	}
+
 	/**
 	 * Return the many-to-many extra fields specification.
 	 *
 	 * If you don't specify a component name, it returns all
 	 * extra fields for all components available.
 	 *
-	 * @param string $component Name of component
-	 * @return array
+	 * @param string $component Deprecated - Name of component
+	 * @return array|null
 	 */
-	public function many_many_extraFields($component = null) {
-		$classes = ClassInfo::ancestry($this);
+	public function manyManyExtraFields($component = null) {
+		if($component) {
+			Deprecation::notice(
+				'3.2',
+				'Please use DataObject::manyManyExtraFieldsForComponent() instead of passing a component name 
+					to manyManyExtraFields()',
+				Deprecation::SCOPE_GLOBAL
+			);
+			return $this->manyManyExtraFieldsForComponent($component);
+		}
 
-		foreach($classes as $class) {
-			if(in_array($class, array('ViewableData', 'Object', 'DataObject'))) continue;
+		return Config::inst()->get($this->class, 'many_many_extraFields', Config::INHERITED);
+	}
+
+	/**
+	 * Return the many-to-many extra fields specification for a specific component.
+	 * @param string $component
+	 * @return array|null
+	 */
+	public function manyManyExtraFieldsForComponent($component) {
+		// Get all many_many_extraFields defined in this class or parent classes
+		$extraFields = (array)Config::inst()->get($this->class, 'many_many_extraFields', Config::INHERITED);
+		// Extra fields are immediately available
+		if(isset($extraFields[$component])) {
+			return $extraFields[$component];
+		}
+
+		// Check this class' belongs_many_manys to see if any of their reverse associations contain extra fields
+		$manyMany = (array)Config::inst()->get($this->class, 'belongs_many_many', Config::INHERITED);
+		$candidate = (isset($manyMany[$component])) ? $manyMany[$component] : null;
+		if($candidate) {
 			$relationName = null;
+			// Extract class and relation name from dot-notation
+			if(strpos($candidate, '.') !== false) {
+				list($candidate, $relationName) = explode('.', $candidate, 2);
+			}
 
-			// Find extra fields for one component
-			if($component) {
-				$SNG_class = singleton($class);
-				$extraFields = $SNG_class->stat('many_many_extraFields');
+			// If we've not already found the relation name from dot notation, we need to find a relation that points
+			// back to this class. As there's no dot-notation, there can only be one relation pointing to this class, 
+			// so it's safe to assume that it's the correct one
+			if(!$relationName) {
+				$candidateManyManys = (array)Config::inst()->get($candidate, 'many_many', Config::UNINHERITED);
 
-				// Extra fields are immediately available on this class
-				if(isset($extraFields[$component])) {
-					return $extraFields[$component];
-				}
-
-				$manyMany = $SNG_class->stat('many_many');
-				$candidate = (isset($manyMany[$component])) ? $manyMany[$component] : null;
-				if($candidate) {
-					$SNG_candidate = singleton($candidate);
-					$candidateManyMany = $SNG_candidate->stat('belongs_many_many');
-
-					// Find the relation given the class
-					if($candidateManyMany) foreach($candidateManyMany as $relation => $relatedClass) {
-						if($relatedClass == $class) {
-							$relationName = $relation;
-							break;
-						}
-					}
-
-					if($relationName) {
-						$extraFields = $SNG_candidate->stat('many_many_extraFields');
-						if(isset($extraFields[$relationName])) {
-							return $extraFields[$relationName];
-						}
+				foreach($candidateManyManys as $relation => $relatedClass) {
+					if($relatedClass === $this->class) {
+						$relationName = $relation;
 					}
 				}
+			}
 
-				$manyMany = $SNG_class->stat('belongs_many_many');
-				$candidate = (isset($manyMany[$component])) ? $manyMany[$component] : null;
-				if($candidate) {
-					$SNG_candidate = singleton($candidate);
-					$candidateManyMany = $SNG_candidate->stat('many_many');
-
-					// Find the relation given the class
-					if($candidateManyMany) foreach($candidateManyMany as $relation => $relatedClass) {
-						if($relatedClass == $class) {
-							$relationName = $relation;
-						}
-					}
-
-					$extraFields = $SNG_candidate->stat('many_many_extraFields');
-					if(isset($extraFields[$relationName])) {
-						return $extraFields[$relationName];
-					}
-				}
-
-			} else {
-				// Find all the extra fields for all components
-				$newItems = (array)Config::inst()->get($class, 'many_many_extraFields', Config::UNINHERITED);
-
-				foreach($newItems as $k => $v) {
-					if(!is_array($v)) {
-						user_error(
-							"$class::\$many_many_extraFields has a bad entry: "
-							. var_export($k, true) . " => " . var_export($v, true)
-							. ". Each many_many_extraFields entry should map to a field specification array.",
-							E_USER_ERROR
-						);
-					}
-				}
-
-				$items = isset($items) ? array_merge($newItems, $items) : $newItems;
+			// If we've found a matching relation on the target class, see if we can find extra fields for it
+			$extraFields = (array)Config::inst()->get($candidate, 'many_many_extraFields', Config::UNINHERITED);
+			if(isset($extraFields[$relationName])) {
+				return $extraFields[$relationName];
 			}
 		}
 
 		return isset($items) ? $items : null;
 	}
 
+	/**
+	 * @deprecated 4.0 Method has been renamed to manyMany()
+	 * @param string $component
+	 * @return array|null
+	 */
+	public function many_many($component = null) {
+		if($component) {
+			Deprecation::notice('3.2', 'Please use manyManyComponent() instead');
+			return $this->manyManyComponent($component);
+		}
+
+		Deprecation::notice('3.2', 'Please use manyMany() instead');
+		return $this->manyMany();
+	}
+
 	/**
 	 * Return information about a many-to-many component.
 	 * The return value is an array of (parentclass, childclass).  If $component is null, then all many-many
 	 * components are returned.
 	 *
-	 * @param string $component Name of component
-	 *
-	 * @return array  An array of (parentclass, childclass), or an array of all many-many components
+	 * @see DataObject::manyManyComponent()
+	 * @param string $component Deprecated - Name of component
+	 * @return array|null An array of (parentclass, childclass), or an array of all many-many components
 	 */
-	public function many_many($component = null) {
-		$classes = ClassInfo::ancestry($this);
-
-		foreach($classes as $class) {
-			// Wait until after we reach DataObject
-			if(in_array($class, array('ViewableData', 'Object', 'DataObject'))) continue;
-
-			if($component) {
-				$manyMany = Config::inst()->get($class, 'many_many', Config::UNINHERITED);
-				// Try many_many
-				$candidate = (isset($manyMany[$component])) ? $manyMany[$component] : null;
-				if($candidate) {
-					$parentField = $class . "ID";
-					$childField = ($class == $candidate) ? "ChildID" : $candidate . "ID";
-					return array($class, $candidate, $parentField, $childField, "{$class}_$component");
-				}
-
-				// Try belongs_many_many
-				$belongsManyMany = Config::inst()->get($class, 'belongs_many_many', Config::UNINHERITED);
-				$candidate = (isset($belongsManyMany[$component])) ? $belongsManyMany[$component] : null;
-				if($candidate) {
-					$childField = $candidate . "ID";
-
-					// We need to find the inverse component name
-					$otherManyMany = Config::inst()->get($candidate, 'many_many', Config::UNINHERITED);
-					if(!$otherManyMany) {
-						user_error("Inverse component of $candidate not found ({$this->class})", E_USER_ERROR);
-					}
-
-					foreach($otherManyMany as $inverseComponentName => $candidateClass) {
-						if($candidateClass == $class || is_subclass_of($class, $candidateClass)) {
-							$parentField = ($class == $candidate) ? "ChildID" : $candidateClass . "ID";
-
-							return array($class, $candidate, $parentField, $childField,
-								"{$candidate}_$inverseComponentName");
-						}
-					}
-					user_error("Orphaned \$belongs_many_many value for $this->class.$component", E_USER_ERROR);
-				}
-			} else {
-				$newItems = (array)Config::inst()->get($class, 'many_many', Config::UNINHERITED);
-				// Validate the data
-				foreach($newItems as $k => $v) {
-					if(!is_string($k) || is_numeric($k) || !is_string($v)) {
-						user_error("$class::\$many_many has a bad entry: "
-						. var_export($k,true). " => " . var_export($v,true) . ".  Each map key should be a"
-						. " relationship name, and the map value should be the data class to join to.", E_USER_ERROR);
-					}
-				}
-				$items = isset($items) ? array_merge($newItems, $items) : $newItems;
-
-				$newItems = (array)Config::inst()->get($class, 'belongs_many_many', Config::UNINHERITED);
-				// Validate the data
-				foreach($newItems as $k => $v) {
-					if(!is_string($k) || is_numeric($k) || !is_string($v)) {
-						user_error("$class::\$belongs_many_many has a bad entry: "
-						. var_export($k,true). " => " . var_export($v,true) . ".  Each map key should be a"
-						. " relationship name, and the map value should be the data class to join to.", E_USER_ERROR);
-					}
-				}
-
-				$items = isset($items) ? array_merge($newItems, $items) : $newItems;
-			}
+	public function manyMany($component = null) {
+		if($component) {
+			Deprecation::notice(
+				'3.2',
+				'Please use DataObject::manyManyComponent() instead of passing a component name to manyMany()',
+				Deprecation::SCOPE_GLOBAL
+			);
+			return $this->manyManyComponent($component);
 		}
 
-		return isset($items) ? $items : null;
+		$manyManys = (array)Config::inst()->get($this->class, 'many_many', Config::INHERITED);
+		$belongsManyManys = (array)Config::inst()->get($this->class, 'belongs_many_many', Config::INHERITED);
+
+		$items = array_merge($manyManys, $belongsManyManys);
+		return $items;
+	}
+
+	/**
+	 * Return information about a specific many_many component. Returns a numeric array of:
+	 * array(
+	 * 	<classname>,		The class that relation is defined in e.g. "Product"
+	 * 	<candidateName>,	The target class of the relation e.g. "Category"
+	 * 	<parentField>,		The field name pointing to <classname>'s table e.g. "ProductID"
+	 * 	<childField>,		The field name pointing to <candidatename>'s table e.g. "CategoryID"
+	 * 	<joinTable>			The join table between the two classes e.g. "Product_Categories"
+	 * )
+	 * @param string $component The component name
+	 * @return array|null
+	 */
+	public function manyManyComponent($component) {
+		$classes = $this->getClassAncestry();
+		foreach($classes as $class) {
+			$manyMany = Config::inst()->get($class, 'many_many', Config::UNINHERITED);
+			// Check if the component is defined in many_many on this class
+			$candidate = (isset($manyMany[$component])) ? $manyMany[$component] : null;
+			if($candidate) {
+				$parentField = $class . "ID";
+				$childField = ($class == $candidate) ? "ChildID" : $candidate . "ID";
+				return array($class, $candidate, $parentField, $childField, "{$class}_$component");
+			}
+
+			// Check if the component is defined in belongs_many_many on this class
+			$belongsManyMany = Config::inst()->get($class, 'belongs_many_many', Config::UNINHERITED);
+			$candidate = (isset($belongsManyMany[$component])) ? $belongsManyMany[$component] : null;
+			if($candidate) {
+				// Extract class and relation name from dot-notation
+				if(strpos($candidate, '.') !== false) {
+					list($candidate, $relationName) = explode('.', $candidate, 2);
+				}
+
+				$childField = $candidate . "ID";
+
+				// We need to find the inverse component name
+				$otherManyMany = Config::inst()->get($candidate, 'many_many', Config::UNINHERITED);
+				if(!$otherManyMany) {
+					throw new LogicException("Inverse component of $candidate not found ({$this->class})");
+				}
+
+				// If we've got a relation name (extracted from dot-notation), we can already work out
+				// the join table and candidate class name...
+				if(isset($relationName) && isset($otherManyMany[$relationName])) {
+					$candidateClass = $otherManyMany[$relationName];
+					$joinTable = "{$candidate}_{$relationName}";
+				} else {
+					// ... otherwise, we need to loop over the many_manys and find a relation that
+					// matches up to this class
+					foreach($otherManyMany as $inverseComponentName => $candidateClass) {
+						if($candidateClass == $class || is_subclass_of($class, $candidateClass)) {
+							$joinTable = "{$candidate}_{$inverseComponentName}";
+							break;
+						}
+					}
+				}
+
+				// If we could work out the join table, we've got all the info we need
+				if(isset($joinTable)) {
+					$parentField = ($class == $candidate) ? "ChildID" : $candidateClass . "ID";
+					return array($class, $candidate, $parentField, $childField, $joinTable);
+				}
+
+				throw new LogicException("Orphaned \$belongs_many_many value for $this->class.$component");
+			}
+		}
 	}
 
 	/**
@@ -2535,7 +2652,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 		return (
 			array_key_exists($field, $this->record)
 			|| $this->db($field)
-			|| (substr($field,-2) == 'ID') && $this->has_one(substr($field,0, -2))
+			|| (substr($field,-2) == 'ID') && $this->hasOneComponent(substr($field,0, -2))
 			|| $this->hasMethod("get{$field}")
 		);
 	}
@@ -2624,7 +2741,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 		}
 		if(Permission::checkMember($member, "ADMIN")) return true;
 
-		if($this->many_many('Can' . $perm)) {
+		if($this->manyManyComponent('Can' . $perm)) {
 			if($this->ParentID && $this->SecurityType == 'Inherit') {
 				if(!($p = $this->Parent)) {
 					return false;
@@ -2808,12 +2925,12 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 			return $obj;
 
 		// Special case for has_one relationships
-		} else if(preg_match('/ID$/', $fieldName) && $this->has_one(substr($fieldName,0,-2))) {
+		} else if(preg_match('/ID$/', $fieldName) && $this->hasOneComponent(substr($fieldName,0,-2))) {
 			$val = $this->$fieldName;
 			return DBField::create_field('ForeignKey', $val, $fieldName, $this);
 
 		// has_one for polymorphic relations do not end in ID
-		} else if(($type = $this->has_one($fieldName)) && ($type === 'DataObject')) {
+		} else if(($type = $this->hasOneComponent($fieldName)) && ($type === 'DataObject')) {
 			$val = $this->$fieldName();
 			return DBField::create_field('PolymorphicForeignKey', $val, $fieldName, $this);
 
@@ -2911,16 +3028,16 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 * @return String
 	 */
 	public function getReverseAssociation($className) {
-		if (is_array($this->many_many())) {
-			$many_many = array_flip($this->many_many());
+		if (is_array($this->manyMany())) {
+			$many_many = array_flip($this->manyMany());
 			if (array_key_exists($className, $many_many)) return $many_many[$className];
 		}
-		if (is_array($this->has_many())) {
-			$has_many = array_flip($this->has_many());
+		if (is_array($this->hasMany())) {
+			$has_many = array_flip($this->hasMany());
 			if (array_key_exists($className, $has_many)) return $has_many[$className];
 		}
-		if (is_array($this->has_one())) {
-			$has_one = array_flip($this->has_one());
+		if (is_array($this->hasOne())) {
+			$has_one = array_flip($this->hasOne());
 			if (array_key_exists($className, $has_one)) return $has_one[$className];
 		}
 
@@ -3192,6 +3309,9 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 
 		$indexes = $this->databaseIndexes();
 
+		// Validate relationship configuration
+		$this->validateModelDefinitions();
+
 		if($fields) {
 			$hasAutoIncPK = ($this->class == ClassInfo::baseDataClass($this->class));
 			DB::require_table($this->class, $fields, $indexes, $hasAutoIncPK, $this->stat('create_table_options'),
@@ -3228,6 +3348,42 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 		$this->extend('augmentDatabase', $dummy);
 	}
 
+	/**
+	 * Validate that the configured relations for this class use the correct syntaxes
+	 * @throws LogicException
+	 */
+	protected function validateModelDefinitions() {
+		$modelDefinitions = array(
+			'db' => Config::inst()->get($this->class, 'db', Config::UNINHERITED),
+			'has_one' => Config::inst()->get($this->class, 'has_one', Config::UNINHERITED),
+			'has_many' => Config::inst()->get($this->class, 'has_many', Config::UNINHERITED),
+			'belongs_to' => Config::inst()->get($this->class, 'belongs_to', Config::UNINHERITED),
+			'many_many' => Config::inst()->get($this->class, 'many_many', Config::UNINHERITED),
+			'belongs_many_many' => Config::inst()->get($this->class, 'belongs_many_many', Config::UNINHERITED),
+			'many_many_extraFields' => Config::inst()->get($this->class, 'many_many_extraFields', Config::UNINHERITED)
+		);
+
+		foreach($modelDefinitions as $defType => $relations) {
+			if( ! $relations) continue;
+
+			foreach($relations as $k => $v) {
+				if($defType === 'many_many_extraFields') {
+					if(!is_array($v)) {
+						throw new LogicException("$this->class::\$many_many_extraFields has a bad entry: "
+							. var_export($k, true) . " => " . var_export($v, true)
+							. ". Each many_many_extraFields entry should map to a field specification array.");
+					}
+				} else {
+					if(!is_string($k) || is_numeric($k) || !is_string($v)) {
+						throw new LogicException("$this->class::$defType has a bad entry: "
+							. var_export($k, true). " => " . var_export($v, true) . ".  Each map key should be a
+							 relationship name, and the map value should be the data class to join to.");
+					}
+				}
+			}
+		}
+	}
+
 	/**
 	 * Add default records to database. This function is called whenever the
 	 * database is built, after the database tables have all been created. Overload
@@ -3789,7 +3945,7 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 */
 	public function hasValue($field, $arguments = null, $cache = true) {
 		// has_one fields should not use dbObject to check if a value is given
-		if(!$this->has_one($field) && ($obj = $this->dbObject($field))) {
+		if(!$this->hasOneComponent($field) && ($obj = $this->dbObject($field))) {
 			return $obj->exists();
 		} else {
 			return parent::hasValue($field, $arguments, $cache);
diff --git a/model/DataQuery.php b/model/DataQuery.php
index f518badf6..94cbd7d17 100644
--- a/model/DataQuery.php
+++ b/model/DataQuery.php
@@ -645,7 +645,7 @@ class DataQuery {
 
 		foreach($relation as $rel) {
 			$model = singleton($modelClass);
-			if ($component = $model->has_one($rel)) {
+			if ($component = $model->hasOneComponent($rel)) {
 				if(!$this->query->isJoinedTo($component)) {
 					$foreignKey = $rel;
 					$realModelClass = ClassInfo::table_for_object_field($modelClass, "{$foreignKey}ID");
@@ -668,7 +668,7 @@ class DataQuery {
 				}
 				$modelClass = $component;
 
-			} elseif ($component = $model->has_many($rel)) {
+			} elseif ($component = $model->hasManyComponent($rel)) {
 				if(!$this->query->isJoinedTo($component)) {
 					$ancestry = $model->getClassAncestry();
 					$foreignKey = $model->getRemoteJoinField($rel);
@@ -690,7 +690,7 @@ class DataQuery {
 				}
 				$modelClass = $component;
 
-			} elseif ($component = $model->many_many($rel)) {
+			} elseif ($component = $model->manyManyComponent($rel)) {
 				list($parentClass, $componentClass, $parentField, $componentField, $relationTable) = $component;
 				$parentBaseClass = ClassInfo::baseDataClass($parentClass);
 				$componentBaseClass = ClassInfo::baseDataClass($componentClass);
diff --git a/model/fieldtypes/ForeignKey.php b/model/fieldtypes/ForeignKey.php
index c5ea889e8..5850abc72 100644
--- a/model/fieldtypes/ForeignKey.php
+++ b/model/fieldtypes/ForeignKey.php
@@ -28,7 +28,7 @@ class ForeignKey extends Int {
 
 	public function scaffoldFormField($title = null, $params = null) {
 		$relationName = substr($this->name,0,-2);
-		$hasOneClass = $this->object->has_one($relationName);
+		$hasOneClass = $this->object->hasOneComponent($relationName);
 
 		if($hasOneClass && singleton($hasOneClass) instanceof Image) {
 			$field = new UploadField($relationName, $title);
diff --git a/security/PermissionCheckboxSetField.php b/security/PermissionCheckboxSetField.php
index 83403f2cd..236b26543 100644
--- a/security/PermissionCheckboxSetField.php
+++ b/security/PermissionCheckboxSetField.php
@@ -269,7 +269,7 @@ class PermissionCheckboxSetField extends FormField {
 			$permission->delete();
 		}
 
-		if($fieldname && $record && ($record->has_many($fieldname) || $record->many_many($fieldname))) {
+		if($fieldname && $record && ($record->hasManyComponent($fieldname) || $record->manyManyComponent($fieldname))) {
 
 			if(!$record->ID) $record->write(); // We need a record ID to write permissions
 
diff --git a/tests/dev/FixtureBlueprintTest.php b/tests/dev/FixtureBlueprintTest.php
index 53c9af684..1e14a9b0c 100644
--- a/tests/dev/FixtureBlueprintTest.php
+++ b/tests/dev/FixtureBlueprintTest.php
@@ -28,7 +28,7 @@ class FixtureBlueprintTest extends SapphireTest {
 		$obj = $blueprint->createObject(
 			'one',
 			array(
-				'ManyMany' =>
+				'ManyManyRelation' =>
 					array(
 						array(
 							"=>FixtureFactoryTest_DataObjectRelation.relation1" => array(),
@@ -48,18 +48,18 @@ class FixtureBlueprintTest extends SapphireTest {
 			)
 		);
 
-		$this->assertEquals(2, $obj->ManyMany()->Count());
-		$this->assertNotNull($obj->ManyMany()->find('ID', $relation1->ID));
-		$this->assertNotNull($obj->ManyMany()->find('ID', $relation2->ID));
+		$this->assertEquals(2, $obj->ManyManyRelation()->Count());
+		$this->assertNotNull($obj->ManyManyRelation()->find('ID', $relation1->ID));
+		$this->assertNotNull($obj->ManyManyRelation()->find('ID', $relation2->ID));
 
 		$this->assertEquals(
 			array('Label' => 'This is a label for relation 1'),
-			$obj->ManyMany()->getExtraData('ManyMany', $relation1->ID)
+			$obj->ManyManyRelation()->getExtraData('ManyManyRelation', $relation1->ID)
 		);
 
 		$this->assertEquals(
 			array('Label' => 'This is a label for relation 2'),
-			$obj->ManyMany()->getExtraData('ManyMany', $relation2->ID)
+			$obj->ManyManyRelation()->getExtraData('ManyManyRelation', $relation2->ID)
 		);
 	}
 
@@ -92,7 +92,7 @@ class FixtureBlueprintTest extends SapphireTest {
 		$obj = $blueprint->createObject(
 			'one',
 			array(
-				'ManyMany' =>
+				'ManyManyRelation' =>
 					'=>FixtureFactoryTest_DataObjectRelation.relation1,' .
 					'=>FixtureFactoryTest_DataObjectRelation.relation2'
 			),
@@ -104,9 +104,9 @@ class FixtureBlueprintTest extends SapphireTest {
 			)
 		);
 
-		$this->assertEquals(2, $obj->ManyMany()->Count());
-		$this->assertNotNull($obj->ManyMany()->find('ID', $relation1->ID));
-		$this->assertNotNull($obj->ManyMany()->find('ID', $relation2->ID));
+		$this->assertEquals(2, $obj->ManyManyRelation()->Count());
+		$this->assertNotNull($obj->ManyManyRelation()->find('ID', $relation1->ID));
+		$this->assertNotNull($obj->ManyManyRelation()->find('ID', $relation2->ID));
 	}
 
 	/**
@@ -119,7 +119,7 @@ class FixtureBlueprintTest extends SapphireTest {
 		$obj = $blueprint->createObject(
 			'one',
 			array(
-				'ManyMany' => '=>UnknownClass.relation1'
+				'ManyManyRelation' => '=>UnknownClass.relation1'
 			),
 			array(
 				'FixtureFactoryTest_DataObjectRelation' => array(
@@ -139,7 +139,7 @@ class FixtureBlueprintTest extends SapphireTest {
 		$obj = $blueprint->createObject(
 			'one',
 			array(
-				'ManyMany' => '=>FixtureFactoryTest_DataObjectRelation.unknown_identifier'
+				'ManyManyRelation' => '=>FixtureFactoryTest_DataObjectRelation.unknown_identifier'
 			),
 			array(
 				'FixtureFactoryTest_DataObjectRelation' => array(
@@ -163,7 +163,7 @@ class FixtureBlueprintTest extends SapphireTest {
 		$obj = $blueprint->createObject(
 			'one',
 			array(
-				'ManyMany' => 'FixtureFactoryTest_DataObjectRelation.relation1'
+				'ManyManyRelation' => 'FixtureFactoryTest_DataObjectRelation.relation1'
 			),
 			array(
 				'FixtureFactoryTest_DataObjectRelation' => array(
diff --git a/tests/dev/FixtureFactoryTest.php b/tests/dev/FixtureFactoryTest.php
index fb26133f1..9d7013e2d 100644
--- a/tests/dev/FixtureFactoryTest.php
+++ b/tests/dev/FixtureFactoryTest.php
@@ -163,11 +163,11 @@ class FixtureFactoryTest_DataObject extends DataObject implements TestOnly {
 	);
 
 	private static $many_many = array(
-		"ManyMany" => "FixtureFactoryTest_DataObjectRelation"
+		"ManyManyRelation" => "FixtureFactoryTest_DataObjectRelation"
 	);
 
 	private static $many_many_extraFields = array(
-		"ManyMany" => array(
+		"ManyManyRelation" => array(
 			"Label" => "Varchar"
 		)
 	);
diff --git a/tests/model/DataListTest.php b/tests/model/DataListTest.php
index 18fbff30a..3ddd195b6 100755
--- a/tests/model/DataListTest.php
+++ b/tests/model/DataListTest.php
@@ -20,6 +20,8 @@ class DataListTest extends SapphireTest {
 		'DataObjectTest_Player',
 		'DataObjectTest_TeamComment',
 		'DataObjectTest_ExtendedTeamComment',
+		'DataObjectTest_EquipmentCompany',
+		'DataObjectTest_SubEquipmentCompany',
 		'DataObjectTest\NamespacedClass',
 		'DataObjectTest_Company',
 		'DataObjectTest_Fan',
diff --git a/tests/model/DataObjectLazyLoadingTest.php b/tests/model/DataObjectLazyLoadingTest.php
index cc6c8fe33..79db4d151 100644
--- a/tests/model/DataObjectLazyLoadingTest.php
+++ b/tests/model/DataObjectLazyLoadingTest.php
@@ -21,6 +21,9 @@ class DataObjectLazyLoadingTest extends SapphireTest {
 		'DataObjectTest_FieldlessSubTable',
 		'DataObjectTest_ValidatedObject',
 		'DataObjectTest_Player',
+		'DataObjectTest_TeamComment',
+		'DataObjectTest_EquipmentCompany',
+		'DataObjectTest_SubEquipmentCompany',
 		'VersionedTest_DataObject',
 		'VersionedTest_Subclass',
 		'VersionedLazy_DataObject',
diff --git a/tests/model/DataObjectTest.php b/tests/model/DataObjectTest.php
index 142200880..4401fe995 100644
--- a/tests/model/DataObjectTest.php
+++ b/tests/model/DataObjectTest.php
@@ -17,6 +17,8 @@ class DataObjectTest extends SapphireTest {
 		'DataObjectTest_ValidatedObject',
 		'DataObjectTest_Player',
 		'DataObjectTest_TeamComment',
+		'DataObjectTest_EquipmentCompany',
+		'DataObjectTest_SubEquipmentCompany',
 		'DataObjectTest\NamespacedClass',
 		'DataObjectTest\RelationClass',
 		'DataObjectTest_ExtendedTeamComment',
@@ -1060,6 +1062,86 @@ class DataObjectTest extends SapphireTest {
 		);
 	}
 
+	protected function makeAccessible($object, $method) {
+		$reflectionMethod = new ReflectionMethod($object, $method);
+		$reflectionMethod->setAccessible(true);
+		return $reflectionMethod;
+	}
+
+	public function testValidateModelDefinitionsFailsWithArray() {
+		Config::nest();
+		
+		$object = new DataObjectTest_Team;
+		$method = $this->makeAccessible($object, 'validateModelDefinitions');
+
+		Config::inst()->update('DataObjectTest_Team', 'has_one', array('NotValid' => array('NoArraysAllowed')));
+		$this->setExpectedException('LogicException');
+
+		try {
+			$method->invoke($object);
+		} catch(Exception $e) {
+			Config::unnest(); // Catch the exception so we can unnest config before failing the test
+			throw $e;
+		}
+	}
+
+	public function testValidateModelDefinitionsFailsWithIntKey() {
+		Config::nest();
+		
+		$object = new DataObjectTest_Team;
+		$method = $this->makeAccessible($object, 'validateModelDefinitions');
+
+		Config::inst()->update('DataObjectTest_Team', 'has_many', array(12 => 'DataObjectTest_Player'));
+		$this->setExpectedException('LogicException');
+
+		try {
+			$method->invoke($object);
+		} catch(Exception $e) {
+			Config::unnest(); // Catch the exception so we can unnest config before failing the test
+			throw $e;
+		}
+	}
+
+	public function testValidateModelDefinitionsFailsWithIntValue() {
+		Config::nest();
+		
+		$object = new DataObjectTest_Team;
+		$method = $this->makeAccessible($object, 'validateModelDefinitions');
+
+		Config::inst()->update('DataObjectTest_Team', 'many_many', array('Players' => 12));
+		$this->setExpectedException('LogicException');
+
+		try {
+			$method->invoke($object);
+		} catch(Exception $e) {
+			Config::unnest(); // Catch the exception so we can unnest config before failing the test
+			throw $e;
+		}
+	}
+
+	/**
+	 * many_many_extraFields is allowed to have an array value, so shouldn't throw an exception
+	 */
+	public function testValidateModelDefinitionsPassesWithExtraFields() {
+		Config::nest();
+		
+		$object = new DataObjectTest_Team;
+		$method = $this->makeAccessible($object, 'validateModelDefinitions');
+
+		Config::inst()->update('DataObjectTest_Team', 'many_many_extraFields',
+			array('Relations' => array('Price' => 'Int')));
+
+		try {
+			$method->invoke($object);
+		} catch(Exception $e) {
+			Config::unnest();
+			$this->fail('Exception should not be thrown');
+			throw $e;
+		}
+
+		Config::unnest();
+	}
+
 	public function testNewClassInstance() {
 		$dataObject = $this->objFromFixture('DataObjectTest_Team', 'team1');
 		$changedDO = $dataObject->newClassInstance('DataObjectTest_SubTeam');
@@ -1078,32 +1160,85 @@ class DataObjectTest extends SapphireTest {
 		$this->assertEquals($changedDO->ClassName, 'DataObjectTest_SubTeam');
 	}
 
+	public function testMultipleManyManyWithSameClass() {
+		$team = $this->objFromFixture('DataObjectTest_Team', 'team1');
+		$sponsors = $team->Sponsors();
+		$equipmentSuppliers = $team->EquipmentSuppliers();
+
+		// Check that DataObject::many_many() works as expected
+		list($class, $targetClass, $parentField, $childField, $joinTable) = $team->manyManyComponent('Sponsors');
+		$this->assertEquals('DataObjectTest_Team', $class,
+			'DataObject::many_many() didn\'t find the correct base class');
+		$this->assertEquals('DataObjectTest_EquipmentCompany', $targetClass,
+			'DataObject::many_many() didn\'t find the correct target class for the relation');
+		$this->assertEquals('DataObjectTest_EquipmentCompany_SponsoredTeams', $joinTable,
+			'DataObject::many_many() didn\'t find the correct relation table');
+
+		// Check that ManyManyList still works
+		$this->assertEquals(2, $sponsors->count(), 'Rows are missing from relation');
+		$this->assertEquals(1, $equipmentSuppliers->count(), 'Rows are missing from relation');
+
+		// Check everything works when no relation is present
+		$teamWithoutSponsor = $this->objFromFixture('DataObjectTest_Team', 'team3');
+		$this->assertInstanceOf('ManyManyList', $teamWithoutSponsor->Sponsors());
+		$this->assertEquals(0, $teamWithoutSponsor->Sponsors()->count());
+
+		// Check many_many_extraFields still works
+		$equipmentCompany = $this->objFromFixture('DataObjectTest_EquipmentCompany', 'equipmentcompany1');
+		$equipmentCompany->SponsoredTeams()->add($teamWithoutSponsor, array('SponsorFee' => 1000));
+		$sponsoredTeams = $equipmentCompany->SponsoredTeams();
+		$this->assertEquals(1000, $sponsoredTeams->byID($teamWithoutSponsor->ID)->SponsorFee,
+			'Data from many_many_extraFields was not stored/extracted correctly');
+
+		// Check subclasses correctly inherit multiple many_manys
+		$subTeam = $this->objFromFixture('DataObjectTest_SubTeam', 'subteam1');
+		$this->assertEquals(2, $subTeam->Sponsors()->count(),
+			'Child class did not inherit multiple many_manys');
+		$this->assertEquals(1, $subTeam->EquipmentSuppliers()->count(),
+			'Child class did not inherit multiple many_manys');
+		// Team 2 has one EquipmentCompany sponsor and one SubEquipmentCompany
+		$team2 = $this->objFromFixture('DataObjectTest_Team', 'team2');
+		$this->assertEquals(2, $team2->Sponsors()->count(),
+			'Child class did not inherit multiple belongs_many_manys');
+
+		// Check many_many_extraFields also works from the belongs_many_many side
+		$sponsors = $team2->Sponsors();
+		$sponsors->add($equipmentCompany, array('SponsorFee' => 750));
+		$this->assertEquals(750, $sponsors->byID($equipmentCompany->ID)->SponsorFee,
+			'Data from many_many_extraFields was not stored/extracted correctly');
+
+		$subEquipmentCompany = $this->objFromFixture('DataObjectTest_SubEquipmentCompany', 'subequipmentcompany1');
+		$subTeam->Sponsors()->add($subEquipmentCompany, array('SponsorFee' => 1200));
+		$this->assertEquals(1200, $subTeam->Sponsors()->byID($subEquipmentCompany->ID)->SponsorFee,
+			'Data from inherited many_many_extraFields was not stored/extracted correctly');
+	}
+
 	public function testManyManyExtraFields() {
 		$player = $this->objFromFixture('DataObjectTest_Player', 'player1');
 		$team = $this->objFromFixture('DataObjectTest_Team', 'team1');
 
 		// Get all extra fields
-		$teamExtraFields = $team->many_many_extraFields();
+		$teamExtraFields = $team->manyManyExtraFields();
 		$this->assertEquals(array(
 			'Players' => array('Position' => 'Varchar(100)')
 		), $teamExtraFields);
 
 		// Ensure fields from parent classes are included
 		$subTeam = singleton('DataObjectTest_SubTeam');
-		$teamExtraFields = $subTeam->many_many_extraFields();
+		$teamExtraFields = $subTeam->manyManyExtraFields();
 		$this->assertEquals(array(
 			'Players' => array('Position' => 'Varchar(100)'),
 			'FormerPlayers' => array('Position' => 'Varchar(100)')
 		), $teamExtraFields);
-		
+
 		// Extra fields are immediately available on the Team class (defined in $many_many_extraFields)
-		$teamExtraFields = $team->many_many_extraFields('Players');
+		$teamExtraFields = $team->manyManyExtraFieldsForComponent('Players');
 		$this->assertEquals($teamExtraFields, array(
 			'Position' => 'Varchar(100)'
 		));
 
 		// We'll have to go through the relation to get the extra fields on Player
-		$playerExtraFields = $player->many_many_extraFields('Teams');
+		$playerExtraFields = $player->manyManyExtraFieldsForComponent('Teams');
 		$this->assertEquals($playerExtraFields, array(
 			'Position' => 'Varchar(100)'
 		));
@@ -1133,7 +1268,7 @@ class DataObjectTest extends SapphireTest {
 
 		// Check that ordering a many-many relation by an aggregate column doesn't fail
 		$player = $this->objFromFixture('DataObjectTest_Player', 'player2');
-		$player->Teams("", "count(DISTINCT \"DataObjectTest_Team_Players\".\"DataObjectTest_PlayerID\") DESC");
+		$player->Teams()->sort("count(DISTINCT \"DataObjectTest_Team_Players\".\"DataObjectTest_PlayerID\") DESC");
 	}
 
 	/**
@@ -1286,13 +1421,13 @@ class DataObjectTest extends SapphireTest {
 				'CurrentStaff'     => 'DataObjectTest_Staff',
 				'PreviousStaff'    => 'DataObjectTest_Staff'
 			),
-			$company->has_many(),
+			$company->hasMany(),
 			'has_many strips field name data by default.'
 		);
 
 		$this->assertEquals (
 			'DataObjectTest_Staff',
-			$company->has_many('CurrentStaff'),
+			$company->hasManyComponent('CurrentStaff'),
 			'has_many strips field name data by default on single relationships.'
 		);
 
@@ -1301,13 +1436,13 @@ class DataObjectTest extends SapphireTest {
 				'CurrentStaff'     => 'DataObjectTest_Staff.CurrentCompany',
 				'PreviousStaff'    => 'DataObjectTest_Staff.PreviousCompany'
 			),
-			$company->has_many(null, false),
+			$company->hasMany(null, false),
 			'has_many returns field name data when $classOnly is false.'
 		);
 
 		$this->assertEquals (
 			'DataObjectTest_Staff.CurrentCompany',
-			$company->has_many('CurrentStaff', false),
+			$company->hasManyComponent('CurrentStaff', false),
 			'has_many returns field name data on single records when $classOnly is false.'
 		);
 	}
@@ -1563,6 +1698,11 @@ class DataObjectTest_Team extends DataObject implements TestOnly {
 		)
 	);
 
+	private static $belongs_many_many = array(
+		'Sponsors' => 'DataObjectTest_EquipmentCompany.SponsoredTeams',
+		'EquipmentSuppliers' => 'DataObjectTest_EquipmentCompany.EquipmentCustomers'
+	);
+
 	private static $summary_fields = array(
 		'Title' => 'Custom Title',
 		'Title.UpperCase' => 'Title',
@@ -1698,6 +1838,25 @@ class DataObjectTest_Company extends DataObject implements TestOnly {
 	);
 }
 
+class DataObjectTest_EquipmentCompany extends DataObjectTest_Company implements TestOnly {
+	private static $many_many = array(
+		'SponsoredTeams' => 'DataObjectTest_Team',
+		'EquipmentCustomers' => 'DataObjectTest_Team'
+	);
+
+	private static $many_many_extraFields = array(
+		'SponsoredTeams' => array(
+			'SponsorFee' => 'Int'
+		)
+	);
+}
+
+class DataObjectTest_SubEquipmentCompany extends DataObjectTest_EquipmentCompany implements TestOnly {
+	private static $db = array(
+		'SubclassDatabaseField' => 'Varchar'
+	);
+}
+
 class DataObjectTest_Staff extends DataObject implements TestOnly {
 	private static $has_one = array (
 		'CurrentCompany'  => 'DataObjectTest_Company',
diff --git a/tests/model/DataObjectTest.yml b/tests/model/DataObjectTest.yml
index b3e5b156b..f5065efef 100644
--- a/tests/model/DataObjectTest.yml
+++ b/tests/model/DataObjectTest.yml
@@ -1,68 +1,82 @@
+DataObjectTest_EquipmentCompany:
+  equipmentcompany1:
+    Name: Company corp
+  equipmentcompany2:
+    Name: 'Team co.'
+DataObjectTest_SubEquipmentCompany:
+  subequipmentcompany1:
+    Name: John Smith and co
 DataObjectTest_Team:
-	team1:
-		Title: Team 1
-	team2:
-		Title: Team 2
-	team3:
-		Title: Team 3
+  team1:
+    Title: Team 1
+    Sponsors: =>DataObjectTest_EquipmentCompany.equipmentcompany1,=>DataObjectTest_EquipmentCompany.equipmentcompany2
+    EquipmentSuppliers: =>DataObjectTest_EquipmentCompany.equipmentcompany2
+  team2:
+    Title: Team 2
+    Sponsors: =>DataObjectTest_EquipmentCompany.equipmentcompany2,=>DataObjectTest_SubEquipmentCompany.subequipmentcompany1
+    EquipmentSuppliers: =>DataObjectTest_EquipmentCompany.equipmentcompany1,=>DataObjectTest_EquipmentCompany.equipmentcompany2
+  team3:
+    Title: Team 3
 DataObjectTest_Player:
-	captain1:
-		FirstName: Captain
-		ShirtNumber: 007
-		FavouriteTeam: =>DataObjectTest_Team.team1
-		Teams: =>DataObjectTest_Team.team1
-		IsRetired: 1
-	captain2:
-		FirstName: Captain 2
-		Teams: =>DataObjectTest_Team.team2
-	player1:
-		FirstName: Player 1
-	player2:
-		FirstName: Player 2
-		Teams: =>DataObjectTest_Team.team1,=>DataObjectTest_Team.team2
+  captain1:
+    FirstName: Captain
+    ShirtNumber: 007
+    FavouriteTeam: =>DataObjectTest_Team.team1
+    Teams: =>DataObjectTest_Team.team1
+    IsRetired: 1
+  captain2:
+    FirstName: Captain 2
+    Teams: =>DataObjectTest_Team.team2
+  player1:
+    FirstName: Player 1
+  player2:
+    FirstName: Player 2
+    Teams: =>DataObjectTest_Team.team1,=>DataObjectTest_Team.team2
 DataObjectTest_SubTeam:
-	subteam1:
-		Title: Subteam 1
-		SubclassDatabaseField: Subclassed 1
-		ExtendedDatabaseField: Extended 1
-		ParentTeam: =>DataObjectTest_Team.team1
-	subteam2_with_player_relation:
-		Title: Subteam 2
-		SubclassDatabaseField: Subclassed 2
-		ExtendedHasOneRelationship: =>DataObjectTest_Player.player1
-	subteam3_with_empty_fields:
-		Title: Subteam 3
+  subteam1:
+    Title: Subteam 1
+    SubclassDatabaseField: Subclassed 1
+    ExtendedDatabaseField: Extended 1
+    ParentTeam: =>DataObjectTest_Team.team1
+    Sponsors: =>DataObjectTest_EquipmentCompany.equipmentcompany1,=>DataObjectTest_EquipmentCompany.equipmentcompany2
+    EquipmentSuppliers: =>DataObjectTest_EquipmentCompany.equipmentcompany1
+  subteam2_with_player_relation:
+    Title: Subteam 2
+    SubclassDatabaseField: Subclassed 2
+    ExtendedHasOneRelationship: =>DataObjectTest_Player.player1
+  subteam3_with_empty_fields:
+    Title: Subteam 3
 DataObjectTest_TeamComment:
-	comment1:
-		Name: Joe
-		Comment: This is a team comment by Joe
-		Team: =>DataObjectTest_Team.team1
-	comment2:
-		Name: Bob
-		Comment: This is a team comment by Bob
-		Team: =>DataObjectTest_Team.team1
-	comment3:
-		Name: Phil
-		Comment: Phil is a unique guy, and comments on team2
-		Team: =>DataObjectTest_Team.team2
+  comment1:
+    Name: Joe
+    Comment: This is a team comment by Joe
+    Team: =>DataObjectTest_Team.team1
+  comment2:
+    Name: Bob
+    Comment: This is a team comment by Bob
+    Team: =>DataObjectTest_Team.team1
+  comment3:
+    Name: Phil
+    Comment: Phil is a unique guy, and comments on team2
+    Team: =>DataObjectTest_Team.team2
 DataObjectTest_Fan:
-	fan1:
-		Name: Damian
-		Favourite: =>DataObjectTest_Team.team1
-	fan2:
-		Name: Stephen
-		Favourite: =>DataObjectTest_Player.player1
-		SecondFavourite: =>DataObjectTest_Team.team2
-	fan3:
-		Name: Richard
-		Favourite: =>DataObjectTest_Team.team1
-	fan4:
-		Name: Mitch
-		Favourite: =>DataObjectTest_SubTeam.subteam1
+  fan1:
+    Name: Damian
+    Favourite: =>DataObjectTest_Team.team1
+  fan2:
+    Name: Stephen
+    Favourite: =>DataObjectTest_Player.player1
+    SecondFavourite: =>DataObjectTest_Team.team2
+  fan3:
+    Name: Richard
+    Favourite: =>DataObjectTest_Team.team1
+  fan4:
+    Name: Mitch
+    Favourite: =>DataObjectTest_SubTeam.subteam1
 DataObjectTest_Company:
-	company1:
-		Name: Company corp
-		Owner: =>DataObjectTest_Player.player1
-	company1:
-		Name: 'Team co.'
-		Owner: =>DataObjectTest_Player.player2
+  company1:
+    Name: Company corp
+    Owner: =>DataObjectTest_Player.player1
+  company1:
+    Name: 'Team co.'
+    Owner: =>DataObjectTest_Player.player2
diff --git a/tests/security/PermissionCheckboxSetFieldTest.php b/tests/security/PermissionCheckboxSetFieldTest.php
index 192bd9488..5d701d122 100644
--- a/tests/security/PermissionCheckboxSetFieldTest.php
+++ b/tests/security/PermissionCheckboxSetFieldTest.php
@@ -46,7 +46,7 @@ class PermissionCheckboxSetFieldTest extends SapphireTest {
 		$this->assertEquals($group->Permissions()->Count(), 0, 'The tested group has no permissions');
 
 		$this->assertEquals($untouchable->Permissions()->Count(), 1, 'The other group has one permission');
-		$this->assertEquals($untouchable->Permissions("\"Code\"='ADMIN'")->Count(), 1,
+		$this->assertEquals($untouchable->Permissions()->where("\"Code\"='ADMIN'")->Count(), 1,
 			'The other group has ADMIN permission');
 
 		$this->assertEquals(DataObject::get('Permission')->Count(), $baseCount, 'There are no orphaned permissions');
@@ -62,14 +62,14 @@ class PermissionCheckboxSetFieldTest extends SapphireTest {
 		$untouchable->flushCache();
 		$this->assertEquals($group->Permissions()->Count(), 2,
 			'The tested group has two permissions permission');
-		$this->assertEquals($group->Permissions("\"Code\"='ADMIN'")->Count(), 1,
+		$this->assertEquals($group->Permissions()->where("\"Code\"='ADMIN'")->Count(), 1,
 			'The tested group has ADMIN permission');
-		$this->assertEquals($group->Permissions("\"Code\"='NON-ADMIN'")->Count(), 1,
+		$this->assertEquals($group->Permissions()->where("\"Code\"='NON-ADMIN'")->Count(), 1,
 			'The tested group has CMS_ACCESS_AssetAdmin permission');
 
 		$this->assertEquals($untouchable->Permissions()->Count(), 1,
 			'The other group has one permission');
-		$this->assertEquals($untouchable->Permissions("\"Code\"='ADMIN'")->Count(), 1,
+		$this->assertEquals($untouchable->Permissions()->where("\"Code\"='ADMIN'")->Count(), 1,
 			'The other group has ADMIN permission');
 
 		$this->assertEquals(DataObject::get('Permission')->Count(), $baseCount+2,
@@ -85,12 +85,12 @@ class PermissionCheckboxSetFieldTest extends SapphireTest {
 		$untouchable->flushCache();
 		$this->assertEquals($group->Permissions()->Count(), 1,
 			'The tested group has 1 permission');
-		$this->assertEquals($group->Permissions("\"Code\"='ADMIN'")->Count(), 1,
+		$this->assertEquals($group->Permissions()->where("\"Code\"='ADMIN'")->Count(), 1,
 			'The tested group has ADMIN permission');
 
 		$this->assertEquals($untouchable->Permissions()->Count(), 1,
 			'The other group has one permission');
-		$this->assertEquals($untouchable->Permissions("\"Code\"='ADMIN'")->Count(), 1,
+		$this->assertEquals($untouchable->Permissions()->where("\"Code\"='ADMIN'")->Count(), 1,
 			'The other group has ADMIN permission');
 
 		$this->assertEquals(DataObject::get('Permission')->Count(), $baseCount+1,
diff --git a/tests/testing/YamlFixtureTest.php b/tests/testing/YamlFixtureTest.php
index 975897191..beaa93f3c 100644
--- a/tests/testing/YamlFixtureTest.php
+++ b/tests/testing/YamlFixtureTest.php
@@ -49,7 +49,7 @@ class YamlFixtureTest extends SapphireTest {
 			$factory->getId("YamlFixtureTest_DataObject", "testobject1")
 		);
 		$this->assertTrue(
-			$object1->ManyMany()->Count() == 2,
+			$object1->ManyManyRelation()->Count() == 2,
 			"Should be two items in this relationship"
 		);
 		$this->assertGreaterThan(0, $factory->getId("YamlFixtureTest_DataObject", "testobject2"));
@@ -58,7 +58,7 @@ class YamlFixtureTest extends SapphireTest {
 			$factory->getId("YamlFixtureTest_DataObject", "testobject2")
 		);
 		$this->assertTrue(
-			$object2->ManyMany()->Count() == 1,
+			$object2->ManyManyRelation()->Count() == 1,
 			"Should be one item in this relationship"
 		);
 	}
@@ -79,7 +79,7 @@ class YamlFixtureTest_DataObject extends DataObject implements TestOnly {
 		"Name" => "Varchar"
 	);
 	private static $many_many = array(
-		"ManyMany" => "YamlFixtureTest_DataObjectRelation"
+		"ManyManyRelation" => "YamlFixtureTest_DataObjectRelation"
 	);
 }
 
diff --git a/tests/testing/YamlFixtureTest.yml b/tests/testing/YamlFixtureTest.yml
index b2a60f7b9..63aed8d6b 100644
--- a/tests/testing/YamlFixtureTest.yml
+++ b/tests/testing/YamlFixtureTest.yml
@@ -6,7 +6,7 @@ YamlFixtureTest_DataObjectRelation:
 YamlFixtureTest_DataObject:
   testobject1:
     Name: TestObject1
-    ManyMany: =>YamlFixtureTest_DataObjectRelation.relation1,=>YamlFixtureTest_DataObjectRelation.relation2
+    ManyManyRelation: =>YamlFixtureTest_DataObjectRelation.relation1,=>YamlFixtureTest_DataObjectRelation.relation2
   testobject2:
     Name: TestObject2
-    ManyMany: =>YamlFixtureTest_DataObjectRelation.relation1
\ No newline at end of file
+    ManyManyRelation: =>YamlFixtureTest_DataObjectRelation.relation1
\ No newline at end of file