Apple Final Cut Pro 7 - Manual (Page 603)

To mark out-of-sync clip items as in sync
1 In the Timeline, select the items that you want to mark as in sync (one video and up to
24 audio items may be marked as in sync).
Out-of-sync indicator
2 Choose Modify > Mark in Sync.
The items are now marked as in sync, although their positions in the Timeline haven’t
changed.
The out-of-sync
indicators disappear.
If you select just the audio and move it out of sync, out-of-sync indicators appear.
The out-of-sync
indicators show the
new offset, not the
original offset.
The Mark in Sync command permanently affects the sync relationship of the selected clip
items in your sequence. Once you’ve modified the sync relationship of clip items, the
only way to restore the original sync relationship is to manually move the clip items into
the old sync relationship and use the Mark in Sync command again, or to delete the clip
items and reedit a new instance of that clip into your sequence from the Browser.
603 Chapter 40 Linking and Editing Video and Audio in Sync