196-97 in the 5.0 Reference ManualCompacting audio files and regions can be an effective way to maximize your storage capabilities, however, it is a DESTRUCTIVE process and CANNOT BE UNDONE.When Compacting, you will permanently alter the orignal "parent"* audio files, that are referenced by the regions residing within the session. The portions of audio files referenced by the audio regions removed from your session, will be deleted, thus consolidating (compacting) the "parent" audio files to only contain the audio actually used in the session. The Padding setting allows you set an amount of extra audio at the beginning and end of each region's boundaries.This is a process normally done near or at the end of the session.Follow steps on page 197 to Compact the selected audio files.* "Parent" audio files are the SDII files used in your Pro Tools session. They are listed in you session's region bin in Bold. Regions are pieces of audio "captured" from an audio file and are displayed in normal text, not in Bold. Pg. 12 in the Pro Tools 5.0 Reference Manual provides additional basic Pro Tools concepts.