Use the Don't compress files like checkbox to identify files that should not be compressed (before sending and during precompression) by file type and/or creator. Files can be identified by type only or by type and creator. For example, the type of a SimpleText file is 'TEXT', and the creator is 'ttxt'.

File type and creator is set by choosing an existing file of the same kind. Click Choose to see or select files that will not be compressed.

Only one file needs to be chosen for a particular type. All files of the same type (and creator, if desired) will be transferred uncompressed as well.