If you were going to go the whole hog, slap the entire MIME type name in the ext...

magnetikonline on July 15, 2014 | parent | context | favorite | on: 3-character filename extensions

If you were going to go the whole hog, slap the entire MIME type name in the extension :) Otherwise I don't think 3-4 character file extensions have really let anyone down in the history of computing.