[Wikitech-l] Wikimedia skins directory

Hi.

The URL for CSS used to be something like this:

//bits.wikimedia.org/skins-1.18/monobook/main.css

Now there's apparently this:

//bits.wikimedia.org/skins-1.20wmf1/monobook/main.css

But this also works:

//bits.wikimedia.org/skins/monobook/main.css

Can someone please explain which should be used? Unexpectedly getting rid of skins-1.18/ is actively breaking the look of certain pages (such as the www portals), but I'm not clear whether I should simply be switching to a new MediaWiki version in the URL or if there's something canonical I can use instead (which would obviously be preferred).

I didn't see anything on the mailing list about this....

MZMcBride