from now on specific per-bot/per-software/per-client
header is mandatory for contacting Wikimedia sites.
Oh, my. And not just to be a bot, or to edit the site manually,
but even to view it. You can't even fetch a single, simple page
now without supplying that header.
If this has been discussed to death elsewhere and represents
some bizarrely-informed consensus, I'll try to spare this list
my belated rantings, but this is a terrible, terrible idea.
Relying on User-Agent represents the very antithesis of
[[Postel's Law]], a rock-solid principle o which the Internet
(used to be) based.