Zefram <zefram(_at_)fysh(_dot_)org> writes:
This touches on an issue that I've been wondering about. I'm not entirely
clear on what the <dnsqueryelement> extension mechanism is for. What kind
of information might it represent? If the URI scheme is intended purely
to represent a <name,type,class> tuple then there is no possible use for
the extension mechanism -- no additional information that one would ever
want to add to the tuple. In considering reasonable usage scenarios I
came up with only one additional element that one might want to use: a
flag meaning "insist on the data being cryptographically authenticated".
The intention was to make sure future extensions aren't disallowed by
the syntax. It could be used to indicate, e.g., that the RD flag
should be set or cleared, if someone do find it useful in the future,
and document it, and there is consensus for it.
Yet another protocol matter that hasn't been addressed so far: how are
domain name labels other than character labels (e.g., binary labels)
to be represented in the URI syntax? Most applications that need to
represent these kinds of labels in character strings use the master file
format defined in the RFCs, but draft-josefsson-dns-url is quite clear
that it doesn't use that syntax. It offers no syntax for binary labels,
and no extension mechanism for future label types.
Can you elaborate? The intention is that, e.g., a binary label with
the ASCII value 0x17 is expressed as dns:%17. There are some text and
examples for this.