The SQLite documentation reads: "Applications that use SQLite as their application file-format should set the Application ID integer to a unique integer so that utilities such as file(1) can determine the specific file type rather than just reporting "SQLite3 Database". A list of assigned application IDs can be seen by consulting the magic.txt file in the SQLite source repository." The documentation doesn't explicitly say how to 1) come up with a unique integer, and 2) insure that it remains unique. However it implies that some such mechanism might exist. A quick reading suggests: 1) Pick an integer not in magic.txt. 2) Get it added to magic.txt Since magic.txt is in the sqlite repository, that would imply contacting someone who has permission to update the sqlite repository. That is what the OP attempted. The sparsity, and age of the entries in magic.txt is a strong suggestion that some other mechanism should be used. The clues file(1) and "magic" suggest searching through unix (or unix-like) documentation, and that might tell you how to determine if an integer you picked is currently registered, and how to register it for yourself.