diff --git a/src/Track.h b/src/Track.h
index 43515f6ef..11e9e42f1 100644
--- a/src/Track.h
+++ b/src/Track.h
@@ -216,6 +216,8 @@ class AUDACITY_DLL_API TrackListIterator
    TrackListNode *cur;
 };
 
+// TrackListCondIterator (base class for iterators that iterate over all tracks)
+// that meet a condition)
 class AUDACITY_DLL_API TrackListCondIterator: public TrackListIterator
 {
    public:
@@ -443,14 +445,3 @@ class AUDACITY_DLL_API TrackFactory
 
 #endif
 
-// Indentation settings for Vim and Emacs and unique identifier for Arch, a
-// version control system. Please do not modify past this point.
-//
-// Local Variables:
-// c-basic-offset: 3
-// indent-tabs-mode: nil
-// End:
-//
-// vim: et sts=3 sw=3
-// arch-tag: 2214d773-8e6c-4117-a03d-36c9722ace52
-
diff --git a/src/TrackPanel.cpp b/src/TrackPanel.cpp
index 41feb7601..8ae2e365f 100644
--- a/src/TrackPanel.cpp
+++ b/src/TrackPanel.cpp
@@ -789,9 +789,9 @@ void TrackPanel::SelectTracksByLabel( LabelTrack *lt )
    }
 }
 
-/// Set selection length to the length of a track -- but if linking is turned
-/// on, use the largest possible selection in the group.  And if it's a stereo
-/// track, do the same for the stereo channels.
+// Set selection length to the length of a track -- but if sync-lock is turned
+// on, use the largest possible selection in the sync-lock group.  
+// If it's a stereo track, do the same for the stereo channels.
 void TrackPanel::SelectTrackLength(Track *t)
 {
    AudacityProject *p = GetActiveProject();
@@ -800,7 +800,7 @@ void TrackPanel::SelectTrackLength(Track *t)
    double minOffset = t->GetOffset();
    double maxEnd = t->GetEndTime();
 
-   // If we have a group and linking is on, check the group tracks
+   // If we have a sync-lock group and sync-lock linking is on, check the tracks in the group.
    if (p->IsSyncLocked() && t1 != NULL)
    {
       for ( ; t1; t1 = it.Next())
@@ -2644,7 +2644,7 @@ void TrackPanel::StartSlide(wxMouseEvent & event)
             // don't capture based on links to label tracks for now (until
             // we can treat individual labels as clips)
             if (mCapturedClipArray[i].clip) {
-               // Iterate over group tracks
+               // Iterate over sync-lock group tracks.
                SyncLockedTracksIterator git(mTracks);
                for ( Track *t = git.First(mCapturedClipArray[i].track);
                      t; t = git.Next() )
@@ -2658,7 +2658,7 @@ void TrackPanel::StartSlide(wxMouseEvent & event)
             // Capture additional clips from NoteTracks
             Track *nt = mCapturedClipArray[i].track;
             if (nt->GetKind() == Track::Note) {
-               // Iterate over group tracks
+               // Iterate over sync-lock group tracks.
                SyncLockedTracksIterator git(mTracks);
                for (Track *t = git.First(nt); t; t = git.Next())
                {
diff --git a/src/effects/ChangeSpeed.cpp b/src/effects/ChangeSpeed.cpp
index c5e6c52f7..165cdeac1 100644
--- a/src/effects/ChangeSpeed.cpp
+++ b/src/effects/ChangeSpeed.cpp
@@ -110,8 +110,9 @@ bool EffectChangeSpeed::Process()
 {
    // Similar to EffectSoundTouch::Process()
 
-   //Iterate over each track
-   //Track::All is needed because this effect needs to introduce silence in the group tracks to keep sync
+   // Iterate over each track.
+   // Track::All is needed because this effect needs to introduce 
+   // silence in the sync-lock group tracks to keep sync
    this->CopyInputTracks(Track::All); // Set up mOutputTracks.
    bool bGoodResult = true;
 
diff --git a/src/effects/Generator.cpp b/src/effects/Generator.cpp
index 8811c1d33..c79253cfa 100644
--- a/src/effects/Generator.cpp
+++ b/src/effects/Generator.cpp
@@ -26,7 +26,8 @@ bool Generator::Process()
 
    BeforeGenerate();
 
-   // Set up mOutputTracks. This effect needs Track::All for grouping
+   // Set up mOutputTracks. 
+   // This effect needs Track::All for sync-lock grouping.
    this->CopyInputTracks(Track::All);
 
    // Iterate over the tracks
diff --git a/src/effects/Repeat.cpp b/src/effects/Repeat.cpp
index ff695f7a2..b71e339b6 100644
--- a/src/effects/Repeat.cpp
+++ b/src/effects/Repeat.cpp
@@ -110,7 +110,8 @@ bool EffectRepeat::TransferParameters( Shuttle & shuttle )
 
 bool EffectRepeat::Process()
 {
-   // Set up mOutputTracks. This effect needs Track::All for grouping
+   // Set up mOutputTracks. 
+   // This effect needs Track::All for sync-lock grouping.
    this->CopyInputTracks(Track::All);
 
    int nTrack = 0;
diff --git a/src/effects/SoundTouchEffect.cpp b/src/effects/SoundTouchEffect.cpp
index 3b9796f90..80478b236 100644
--- a/src/effects/SoundTouchEffect.cpp
+++ b/src/effects/SoundTouchEffect.cpp
@@ -57,7 +57,7 @@ bool EffectSoundTouch::Process()
    }
    
    //Iterate over each track
-   //Track::All is needed for group behavior
+   // Needs Track::All for sync-lock grouping.
    this->CopyInputTracks(Track::All);
    bool bGoodResult = true;
 
diff --git a/src/effects/nyquist/Nyquist.cpp b/src/effects/nyquist/Nyquist.cpp
index e18e50678..5a128d4fd 100644
--- a/src/effects/nyquist/Nyquist.cpp
+++ b/src/effects/nyquist/Nyquist.cpp
@@ -566,7 +566,7 @@ bool EffectNyquist::Process()
    }
 
    // We must copy all the tracks, because Paste needs label tracks to ensure
-   // correct group behavior when the timeline is affected; then we just want
+   // correct sync-lock group behavior when the timeline is affected; then we just want
    // to operate on the selected wave tracks
    this->CopyInputTracks(Track::All);
    SelectedTrackListOfKindIterator iter(Track::Wave, mOutputTracks);
@@ -584,9 +584,9 @@ bool EffectNyquist::Process()
 
    mDebugOutput = "";
 
-   // Keep track of whether the current track is first selected in its group
+   // Keep track of whether the current track is first selected in its sync-lock group
    // (we have no idea what the length of the returned audio will be, so we have
-   // to handle group behavior the "old" way).
+   // to handle sync-lock group behavior the "old" way).
    mFirstInGroup = true;
    Track *gtLast = NULL;