Rob Church wrote:
I'm quite willing to add these magic words, but there is one question which needs answering before this happens; what should be done with a {{TALKSPACE}} or similar tag if the current namespace doesn't *have* a talk namespace?
There's an internal MediaWiki function called Namespace::getTalk() that does this. It's used quite a lot, so I'd expect it'll continue to be maintained in some form. Given that, I see no reason not to expose the same behavior to users.
By the way, now that there's apparently an easy way to add "parser functions", how about that {{urlencode:}} function I've been asking for? Among other things, having it would mean we'd no longer have to create two versions of each variable, one with an "E" suffix and one without.