The format of email addresses is local-part@domain where the local part may be up to 64 octets long and the domain may have a maximum of 255 octets.[4] The formal definitions are in RFC 5322 (sections 3.2.3 and 3.4.1) and RFC 5321—with a more readable form given in the informational RFC 3696[5] and the associated errata. Note that unlike the syntax of RFC 1034,[6] and RFC 1035[7] there is no trailing period in the domain name.