John C Klensin wrote: > I would assume that, if someone were revising TCP or IP fifty > years hence, they would end up creating new text, rather than > moving a lot of technical text forward, and that they would do > so for all sorts of technical reasons independent of copyright > constraints. Now I'm confused. When we revise a technical specification in IETF, we try (to some degree) to avoid creating new text unless necessary, for fear of introducing subtle incompatibilities. Why wouldn't "someone" fifty years hence have similar concerns? I'll grant that the text in a lot of these old RFCs looks a bit dated and imprecise by now. But if I were revising TCP, I'd still use RFC 793 as a starting point, and the resulting documents would probably qualify as "derivative works". Keith p.s. Regarding the IPv4 to IPv6 comparison, one could argue that the IPv6 spec _should_ have included more text from RFC 793, as there are indeed subtle differences between the IPv4 and IPv4 protocols that have caused unanticipated problems. _______________________________________________ Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf