In these appendices, we have reproduced the grammar for HTML, the specification of URLs, the protocol specification for HTTP, and some relevant pieces of the MIME specification, to the best of our ability. As usual, the secretary will disavow any knowledge if you find errors or inconsistencies between these versions, and the living, true standards documents, obtainable through your RFC or IETF draft server.
These specifications are written in a rather formal language, so first we introduce the idea of grammar, as used by networking and computing people.