On this page, I've just got together some parts of different pages about the contextual and added the missing descriptions.

• Remove: will remove the file from the playlist
• Crop: will delete all the files not selected and keep the selected one in the playlist
• Show file info special: see here Tag displaying
• Fix mp3 header:To correct the length of your files for a gapless reading (see here for more information)
• masstagger: See here:Masstagger
• MP4 utilities:
  • Convert to mp4: will put the file in an mp4 Container. You can choose to do it in the same directory or not. See here Tags .
  • Extract mp4 track(s): will extract the contained file and give it back into its native format. You can choose to do it in the same directory or not. See here Tags.
  • Optimize mp4 layout: It restructures the layout of the MP4 a bit IIRC.
• Convert: See here Diskwriter
• Database search: will search in the database the info linked to the selected field. For more information, see here: Database search
• Create ogg preview: will create an ogg preview of the file, it is not an ogg converter. To configure it: See here
  
• Search command: will search an action to perform (quicktag replaygain etc..) just type the wanted action.
• Write Audio CD: For more information, see here CD writer
• Edit:
  
  • Cut tracks: will do the same as Ctrl+X: copy the file in the clipboard and removes it from the playlist
  • Copy tracks: will do the same as Ctrl+C: copy the files in the clipboard.
  • Collect tracks: will add the track(s) to the clipboard with those already in it
  • Paste tracks: will do the same as Ctrl+V: paste the tracks at the end of the playlist
  • Insert tracks: will insert the tracks before the selected file
• Play: will start to play the selected file
• Database:
  • Reload info from file(s): will reload the tags and information from the file instead of from the database
  • Reload info from files if changed: will see if the file has been changed since it has been added to the database and reload info only if it waschanged
  • Rewrite tags from database: will rewrite the tags into the file from the database, useful if you did something wrong with the masstagger
  • Remove tags from files: will remove all the tags from the file
  • Remove file from the database: will removce the file from the database (not itself)
• Copy name: will copy the name of the file in the clipboard. you will be able to paste it for personal use
• Open directory: will open the directory of the file. Useful to delete files or correct the name of the files, check the conversion etc...
• Replaygain: See here Replaygain
• freedb: See here: Freedb
• Properties: See here Tag displaying
• Save to playlist: See here Creating/saving a playlist from selected files
• Send to playlist: See here Creating/saving a playlist from selected files
• Massdelete (optional): See here: Adding and suppressing files from foobar
• Quicktag (optional): See here: Quicktag

Edit the context menu

If you find that the contextual menu is too long or heavy, you can supress several entries and reorganize them as you want, which could lighten the use of foobar.You can Remove, Rename, move up/down or insert entries. It is quite straightforward and simple of use. If it is too messy, you can Reset the menu. Another proof of the foobar modularity.