Some time ago a new feature has been added to AniDB which may at first look confusing: Every episode is accompanied by a 0-byte file, marked with an almost white background and without any special attributes like group, source or quality. These files are called "generic files" and can help you add even those episodes to your MyList that can't (or shouldn't) be represented by a regular file-entry.
So, what can they be used for?
You can add () such generic files to your MyList just like regular files, but they have a new property, type, which also illustrates their use:
If there's any additional info about this episode you want to preserve, just enter it in the comment-field.
How can I set the type for many generic files at once?
After you add all the generic files to your MyList like you would do for regular files, go to your MyList and expand it using the + icon until you see the files. There you check all the generics you want to change the type of, then scroll down and select the type from the drop-down menu (you have to scroll down a little until you see 'change generic state to') and select the type you wish to apply for the generic files. If you only have generic files added for the anime, then you just need to scroll down to the end of the file list for that anime and check the 'select all' checkbox and set the generic state for them.
How can I easily add several generic files at once?
By using Add anime to MyList found under Episode list on every anime page. Note that it will have a different meaning if the episodes are expanded by group: Add selected to MyList.