Sentence:  BBCFiles is a BBC file converter that converts between some of the various types of files used by BBC emulators on Acorn & PC formats. It supports 6502Em style applications & scripts, /ssd dfs disc images (supporting watford double <WSD>catalogue</WSD>), vanilla directories, /zip of bbc files with /inf files (with limitations) and directory of bbc files with /inf files. 
Meaning of the word marked with <WSD> tags:  A directory listing.