RFC 4151, "The 'tag' URI Scheme", October 2005Source of RFC: IETF - NON WORKING GROUP
Area Assignment: app
See Also: RFC 4151w/ inline errata
Errata ID: 1485
Publication Format(s) : TEXT
Reported By: Tony Finch
Date Reported: 2008-08-08
Verifier Name: Alexey Melnikov
Date Verified: 2010-05-11
Section 2.1 says:
emailAddress = 1*(alphaNum /"-"/"."/"_") "@" DNSname
It should say:
emailAddress = addr-spec ; addr-spec from RFC 2822/5322
The syntax as specified does not allow characters such as + which are commonly found in email addresses.
Alexey: this is not quite right either, as addr-spec allows various characters that need %-encoding in URIs.