This works, returning an HTML page:
This used to work, returning a feed:
That doesn't work anymore, though, and these don't work, either:
- https://stackoverflow.com/feeds/tag/cocoa%20or%20carbon%20or%20core-graphics%20or%20core-foundation
- https://stackoverflow.com/feeds/tag?tagnames=cocoa%2bor%2bcarbon%2bor%2bcore-graphics%2bor%2bcore-foundation&sort=newest
- https://stackoverflow.com/feeds/tag?tagnames=cocoa+or+carbon+or+core-graphics+or+core-foundation&sort=newest
- https://stackoverflow.com/feeds/tag?tagnames=cocoa%20or%20carbon%20or%20core-graphics%20or%20core-foundation&sort=newest
The second of those is actually linked from the first page.
All of the URLs that don't work return 404.
AND searches (e.g., “cocoa carbon”) do work.