MIME type <file format, protocol, multimedia> The unique identifier used for different file types when conveyed across a {MIME}-based {protocol} such as {MIME} {e-mail} or {HTTP}. Registration of MIME types is explained in {RFC 2048}. Official MIME types (ftp://ftp.isi.edu/in-notes/iana/assignments/media-types/media-types). (1998-02-10)