diff --git a/src/pe/ccd/ICCD.h b/src/pe/ccd/ICCD.h
index d3922b5edf3e7b17d5bf2e81b48a0f4f1fbab650..b47a301e4f4515b90dd7b53a756f6e34822b5106 100644
--- a/src/pe/ccd/ICCD.h
+++ b/src/pe/ccd/ICCD.h
@@ -33,12 +33,14 @@ namespace ccd {
 
 class ICCD : private NonCopyable {
 public:
-   virtual ~ICCD() {};
+   virtual ~ICCD() {}
 
+   /// Generates a list of possible contact pairs.
+   /// This list is also stored in the member variable contacts_ for reuse lateron.
    virtual PossibleContacts& generatePossibleContacts( WcTimingTree* tt = NULL ) = 0;
    PossibleContacts& getPossibleContacts() {return contacts_;}
 
-   virtual void reloadBodies() {};
+   virtual void reloadBodies() {}
    virtual int  getObservedBodyCount() const = 0;
 protected:
    PossibleContacts contacts_;
diff --git a/src/pe/fcd/IFCD.h b/src/pe/fcd/IFCD.h
index 63b7e5a4f53c672b9fd2a03942dbc3743213e02a..0fb86fc595ce0c4bfedb3096a4ddaf5b6a325c66 100644
--- a/src/pe/fcd/IFCD.h
+++ b/src/pe/fcd/IFCD.h
@@ -37,7 +37,18 @@ class IFCD : private NonCopyable{
 public:
    virtual ~IFCD() {};
 
+   ///
+   /// \brief generates a list of actual collisions
+   ///
+   /// Takes a list of possible contacts (pair of BodyIDs) and checks them
+   /// for actual collision. All generated contacts are stored in the member variable
+   /// contacts_ for later reuse.
+   /// Returns a list containing all contact points detected.
+   /// \param possibleContacts list of possible contacts generated by coarse collision detection
+   /// \return list of actual contacts
+   ///
    virtual Contacts& generateContacts(PossibleContacts& possibleContacts) = 0;
+   /// returns saved list of contacts
    Contacts& getContacts() {return contacts_;}
 protected:
    Contacts contacts_;