what's III+ suffixes for use in organizing program

[ArtL7@xxxxxxxx]

I'm using a normally useful organizing/tracking program called Enfish
tracker, that, unfortunately, can't track or word serach my Xywrite files. I
can manually add a file-type, though. Do Xywrite III plus files have any file
extension suffixes we can't see? All I see , in most cases, is the name of
the file, say , LANZA, but no suffixes. Are there any? Best, Art