diff --git a/src/utility/objaddr.rs b/src/utility/objaddr.rs
index c402f5d..f1896ef 100644
--- a/src/utility/objaddr.rs
+++ b/src/utility/objaddr.rs
@@ -4,6 +4,11 @@
 
 use std::collections::HashMap;
 
+/// This trait allows ObjAddr to hold references to Multiple kinds of structs
+/// 
+///  - Lock
+///  - Condition
+///  - Sémaphore
 pub trait SynchObj { }
 
 /// Brief Definition of object identifiers: