Inded. The old RFCs are just the tip of the iceberg, and in the end you have to pretty much ask "What would BIND do?". Zone master files are a great example of

Inded. The old RFCs are just the tip of the iceberg, and in the end you have to pretty much ask "What would BIND do?". Zone master files are a great example of this. There's no official grammar and so there are subtle differences in the way different DNS servers parse them. Its also easy to under-estimate and not notice for example, until you've written a lexer or two, that the grammar is context sensitive and ambiguous... so I'd almost guarantee that trust-dns can be made to interpret one differently to BIND, Knot, or unbound.