An IFID is a specific type of UUID used for uniquely identifying both new and legacy works of interactive fiction.
An IFID may only contain digits, letters, and hyphens.
See section 2.2 of the Treaty of Babel.
Since this is not part of the Treaty of Babel, this advice can't be official, but here's what to do.
STEP ONE: Determine the IFID of your game.
- If your game was previously released to the public, use the MD5 hash of the earliest released version of the main "story file" for your game.
- If your game has never been released to the public, use any UUID generator (such as the TADS IFID Generator page) to get one.
STEP TWO: Insert the string "UUID://XXXXXXXXXXXXXXXX//" into your story file, where XXXXXXXXXXXXXXXX is the IFID you determined in step one.
<!-- UUID://XXXXXXXXXXXXXXXX// -->
as a comment anywhere in your HTML file.
By putting UUID:// in front of your IFID, and // after your IFID, you make it possible for automated tools like Babel to find it.