| RFC | Status | Reference | Notes |
|---|---|---|---|
| 3513 | Obsolete | R. Hinden; S. Deering (April 2003). IP Version 6 Addressing Architecturen. Network Working Group. doi:10.17487/RFC3513. RFC 3513. | Obsoletes RFC 2373. Obsoleted by RFC 4291. |
| 3514 | Informational | S. Bellovin (1 April 2003). The Security Flag in the IPv4 Header. Network Working Group. doi:10.17487/RFC3514. RFC 3514. | This is an April Fools' Day Request for Comments. |
| 3540 | Historic | N. Spring; D. Wetherall; D. Ely (June 2003). Robust Explicit Congestion Notification (ECN) Signaling with Nonces. Network Working Group. doi:10.17487/RFC3540. RFC 3540. | |
| 3596 | Internet Standard | S. Thomson; C. Huitema; V. Ksinant; M. Souissi (October 2003). DNS Extensions to Support IP Version 6. Network Working Group. doi:10.17487/RFC3596. RFC 3596. | Obsoletes RFC 3152 and 1886. |
