( Originating from discussion at https://github.com/mrdoob/three.js/issues/17071 )
When pinned posts contain “rules” for the forum/category, it is inconvenient that they “disappear” after being viewed once. When visiting the forum again after several months, I had forgotten that the pinned posts even exist.
Ha I clicked on a pinned post just to see if it would disappear forever and now I don’t know how to get it back 
Ok, in the absence of any dissenting voices I’ll go ahead and change the setting 
Good! Now a pinned post that I hadn’t opened yet was kept pinned after opening it. However, the already unpinned posts are still unpinned. Is there a way to “bump” the pins on those posts? Maybe they must be resubmitted?
I’m had to track down the old posts and re-pin them - can you check again?
Now that they are more prominent, they could do with a bit more effort. If anyone want to post suggestions here, I’ll update them.
It worked!