On Thu, Apr 26, 2001 at 05:52:10AM +1000, Daniel Stone wrote: > Yes, I know this. The bits are officially "reserved" in the RFC. Some people > took this to mean, "must be zero".
This reminds me of my favourite quote from RFC2795: The Version, Sequence Number, Protocol Number, and Reserved fields are 32 bit unsigned integers. For IMPS version 1.0, the Version must be 1. Reserved must be 0 and will always be 0 in future uses. It is included because every other protocol specification includes a "future use" reserved field which never, ever changes and is therefore a waste of bandwidth and memory. [6] [7] [8]. (Reference 7 is in fact to the TCP standard :) Richard Braakman