Date: Mon, 27 Jan 1997 13:34:24 -0800 (PST) From: Chris Newman <Chris.Newman@innosoft.com> Subject: Re: Relative URLs, // and ; In-Reply-To: <firstname.lastname@example.org> To: Tim Berners-Lee <email@example.com> Cc: IETF URI list <firstname.lastname@example.org> Message-Id: <Pine.SOL.3.95.970127132934.28359Qemail@example.com> On Mon, 27 Jan 1997, Tim Berners-Lee wrote: > > > How is ';' involved in relative URLs? > > Semicolons were introduced to allow elements to be specified by name rather > than > position, for spaces which were best seen as matrices rather than trees. > In this case it is only sensible for relative URls which start with ";" to > take a > set of attribute values which are different. This implies > 1. attributes can only occur once (unless you have a syntax for removing a > particular occurrence) and > 2. a missed value is equivalent to an unspecified value > (so you can remove an occurrence by setting its value to empty) > 3. attributes are unordered > > So relative to > //moremaps.com/us/ma/cambridge;scale=50000;roads=main > or the equivalent > //moremaps.com/us/ma/cambridge;roads=main;scale=50000 > > URI ;scale=25000 > gives //moremaps.com/us/ma/cambridge;scale=25000;roads=main > > and ;roads > gives //moremaps.com/us/ma/cambridge;scale=50000 > > and ;roads= > gives //moremaps.com/us/ma/cambridge;scale=50000;roads= > > and ;rivers=all > gives //moremaps.com/us/ma/cambridge;scale=50000;roads=main;rivers=all I very much like this model. Unfortunately, RFC 1808 seems to contradict this model. It seems to say that if the relative URL includes any parameter, it replaces *all* the parameters of the base URL. This is certainly a problem for the IMAP URL scheme.