.hlp Description .hpj project file (plain text?); contains a list of all .rtf files to compile into the .hlp file and some additional information .cnt Table of Contents (TOC) file. .rtf actual text content in Rich Text Format-format .bmp .dib .wmf .shg picture-files in various formats: .bmp or .dib, .wmf .shg .fts .ftg Full Text Search; used for searching through the text of help documents .ann file with annotations (plain text?) .bmk file with bookmarks (plain text?)