diff --git a/core/model/DataObject.php b/core/model/DataObject.php
index 5231a2652..ad86e2c47 100755
--- a/core/model/DataObject.php
+++ b/core/model/DataObject.php
@@ -823,10 +823,6 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 */
 	protected function onBeforeWrite() {
 		$this->brokenOnWrite = false;
-
-		// DEPRECATED 2.3: use onBeforeWrite()
-		$dummy = null;
-		$this->extend('augmentBeforeWrite', $dummy);
 		
 		$dummy = null;
 		$this->extend('onBeforeWrite', $dummy);
@@ -841,10 +837,6 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 	 * @uses DataObjectDecorator->onAfterWrite()
 	 */
 	protected function onAfterWrite() {
-		// DEPRECATED 2.3: use onAfterWrite()
-		$dummy = null;
-		$this->extend('augmentAfterWrite', $dummy);
-		
 		$dummy = null;
 		$this->extend('onAfterWrite', $dummy);
 	}
@@ -902,9 +894,6 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 			}
 		}
 		
-		// DEPRECATED 2.3: use populateDefaults()
-		$this->extend('augmentPopulateDefaults');
-		
 		$this->extend('populateDefaults');
 	}
 
@@ -2915,9 +2904,6 @@ class DataObject extends ViewableData implements DataObjectInterface, i18nEntity
 				DB::alteration_message("Added default records to $className table","created");
 			}
 		}
-
-		// DEPRECATED 2.3: Use requireDefaultRecords()
-		$this->extend('augmentDefaultRecords', $dummy);
 		
 		// Let any extentions make their own database default data
 		$this->extend('requireDefaultRecords', $dummy);
diff --git a/core/model/SiteTree.php b/core/model/SiteTree.php
index ceb875a92..50c9d5cb2 100755
--- a/core/model/SiteTree.php
+++ b/core/model/SiteTree.php
@@ -660,10 +660,6 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 			return $this->$method($member);
 		}
 		
-		// DEPRECATED 2.3: Use can()
-		$results = $this->extend('alternateCan', $member);
-		if($results && is_array($results)) if(!min($results)) return false;
-		
 		$results = $this->extend('can', $member);
 		if($results && is_array($results)) if(!min($results)) return false;
 
@@ -694,10 +690,6 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 
 		if($member && Permission::checkMember($member, "ADMIN")) return true;
 		
-		// DEPRECATED 2.3: use canAddChildren() instead
-		$results = $this->extend('alternateCanAddChildren', $member);
-		if($results && is_array($results)) if(!min($results)) return false;
-		
 		$results = $this->extend('canAddChildren', $member);
 		if($results && is_array($results)) if(!min($results)) return false;
 		
@@ -729,10 +721,6 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 		// admin override
 		if($member && Permission::checkMember($member, array("ADMIN", "SITETREE_VIEW_ALL"))) return true;
 		
-		// DEPRECATED 2.3: use canView() instead
-		$results = $this->extend('alternateCanView', $member);
-		if($results && is_array($results)) if(!min($results)) return false;
-		
 		// decorated access checks
 		$results = $this->extend('canView', $member);
 		if($results && is_array($results)) if(!min($results)) return false;
@@ -788,10 +776,6 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 			return true;
 		}
 		
-		// DEPRECATED 2.3: use canDelete() instead
-		$results = $this->extend('alternateCanDelete', $memberID);
-		if($results && is_array($results)) if(!min($results)) return false;
-		
 		// decorated access checks
 		$results = $this->extend('canDelete', $memberID);
 		if($results && is_array($results)) if(!min($results)) return false;
@@ -832,10 +816,6 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 
 		if($member && Permission::checkMember($member, "ADMIN")) return true;
 		
-		// DEPRECATED 2.3: use canCreate() instead
-		$results = $this->extend('alternateCanCreate', $member);
-		if($results && is_array($results)) if(!min($results)) return false;
-		
 		// decorated permission checks
 		$results = $this->extend('canCreate', $member);
 		if($results && is_array($results)) if(!min($results)) return false;
@@ -868,10 +848,6 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 		else $memberID = Member::currentUserID();
 		
 		if($memberID && Permission::checkMember($memberID, array("ADMIN", "SITETREE_EDIT_ALL"))) return true;
-
-		// DEPRECATED 2.3: use canEdit() instead
-		$results = $this->extend('alternateCanEdit', $memberID);
-		if($results && is_array($results)) if(!min($results)) return false;
 		
 		// decorated access checks
 		$results = $this->extend('canEdit', $memberID);
@@ -907,10 +883,6 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 		
 		if($member && Permission::checkMember($member, "ADMIN")) return true;
 		
-		// DEPRECATED 2.3: use canPublish() instead
-		$results = $this->extend('alternateCanPublish', $member);
-		if($results && is_array($results)) if(!min($results)) return false;
-		
 		// If we have a result, then that means at least one decorator specified alternateCanPublish
 		// Allow the permission check only if *all* voting decorators allow it.
 		$results = $this->extend('canPublish', $member);
@@ -1180,9 +1152,6 @@ class SiteTree extends DataObject implements PermissionProvider,i18nEntityProvid
 		$currentLang = ($this->hasExtension('Translatable')) ? Translatable::get_current_locale() : i18n::get_locale();
 		$tags .= "<meta http-equiv=\"Content-Language\" content=\"". i18n::convert_rfc1766($currentLang) ."\"/>\n";
 		
-		// DEPRECATED 2.3: Use MetaTags
-		$this->extend('updateMetaTags', $tags);
-		
 		$this->extend('MetaTags', $tags);
 
 		return $tags;
diff --git a/security/Group.php b/security/Group.php
index 0add3c65c..a82421b50 100644
--- a/security/Group.php
+++ b/security/Group.php
@@ -338,10 +338,6 @@ class Group extends DataObject {
 	public function canEdit($member = null) {
 		if(!$member || !(is_a($member, 'Member')) || is_numeric($member)) $member = Member::currentUser();
 		
-		// DEPRECATED 2.3: use canView() instead
-		$results = $this->extend('alternateCanView', $member);
-		if($results && is_array($results)) if(!min($results)) return false;
-		
 		// decorated access checks
 		$results = $this->extend('canEdit', $member);
 		if($results && is_array($results)) if(!min($results)) return false;
@@ -372,10 +368,6 @@ class Group extends DataObject {
 	public function canView($member = null) {
 		if(!$member || !(is_a($member, 'Member')) || is_numeric($member)) $member = Member::currentUser();
 		
-		// DEPRECATED 2.3: use canView() instead
-		$results = $this->extend('alternateCanView', $member);
-		if($results && is_array($results)) if(!min($results)) return false;
-		
 		// decorated access checks
 		$results = $this->extend('canView', $member);
 		if($results && is_array($results)) if(!min($results)) return false;