addFmtLib - What are the options for the 'fmtSearch' parameter?

The 'fmtSearch' parameter specifies how the new format library is added to the session's format search order. The options are: 'APPEND' (adds it to the end of the search list, default), 'INSERT' (adds it to the beginning of the search list), 'REPLACE' (replaces the entire search list with this library), and 'NONE' (adds the library without modifying the search list).