File Buddy help | Renaming | Pattern-based renaming
Other options
Shorten names longer than n characters
To shorten any file name which exceeds the given maximum number of characters, check this box. The specified maximum includes the name and any extension.
Preserve extensions
If this option on, File Buddy will remove the extension, create the new name, and then append the original extension. If this option is off, all changes are applied to the entire name, includking any extension.
Rename Files/Folders
To limit the kind of items renamed to files or folders, use this option.