Maximum length of a MIME Content-Type header field?
问题 I'm just designing the schema for a database table which will hold details of email attachments - their size in bytes, filename and content-type (i.e. "image/jpg", "audio/mp3", etc). Does anybody know the maximum length that I can expect a content-type to be? 回答1: I hope I havn't misread, but it looks like the length is max 127/127 or 255 total . RFC 4288 has a reference in 4.2 (page 6): Type and subtype names MUST conform to the following ABNF: type-name = reg-name subtype-name = reg-name