RFC 2368 (rfc2368) - Page 2 of 10
The mailto URL scheme
Alternative Format: Original Text Document
RFC 2368 The mailto URL scheme July 1998 mailtoURL = "mailto:" [ to ] [ headers ] to = #mailbox headers = "?" header *( "&" header ) header = hname "=" hvalue hname = *urlc hvalue = *urlc "#mailbox" is as specified in RFC 822 [RFC 822]. This means that it consists of zero or more comma-separated mail addresses, possibly including "phrase" and "comment" components. Note that all URL reserved characters in "to" must be encoded: in particular, parentheses, commas, and the percent sign ("%"), which commonly occur in the "mailbox" syntax. "hname" and "hvalue" are encodings of an RFC 822 header name and value, respectively. As with "to", all URL reserved characters must be encoded. The special hname "body" indicates that the associated hvalue is the body of the message. The "body" hname should contain the content for the first text/plain body part of the message. The mailto URL is primarily intended for generation of short text messages that are actually the content of automatic processing (such as "subscribe" messages for mailing lists), not general MIME bodies. Within mailto URLs, the characters "?", "=", "&" are reserved. Because the "&" (ampersand) character is reserved in HTML, any mailto URL which contains an ampersand must be spelled differently in HTML than in other contexts. A mailto URL which appears in an HTML document must use "&" instead of "&". Also note that it is legal to specify both "to" and an "hname" whose value is "to". That is, mailto:addr1%2C%20addr2 is equivalent to mailto:?to=addr1%2C%20addr2 is equivalent to mailto:addr1?to=addr2 8-bit characters in mailto URLs are forbidden. MIME encoded words (as defined in [RFC 2047]) are permitted in header values, but not for any part of a "body" hname. Hoffman, et. al. Standards Track
