MySQL

I can't enter my own mimetype?
Defining mimetypes is of no use, if you can't put transformations on them. Otherwise you could just put a comment on the field. Because entering your own mimetype will cause serious syntax checking issues and validation, this introduces a high-risk false-user-input situation. Instead you have to initialize mimetypes using functions or empty mimetype definitions. Plus, you have a whole overview of available mimetypes.