Was sorting through my PMs earlier, and had an idea.

Is there any chance of a sticky ability for our own private use? On the guild, whenever a subbed thread or PM is posted in, it is bumped to the top. Therefore, for anyone who has a number of threads/PMs, they are shuffled around in latest post order, which may separate threads that are more important/kept track of. For instance, I have a PM RP, and a CS PM for the same RP given that PMs don't have the multiple tabs a regular thread has. When the RP is posted in, along with any other PMs, the CS PM gets pushed down the list, which requires me to go searching for it if I need to reference. With private pins, I, or anyone else for that matter, could keep them at the top and/or together so they don't get lost.

Anyway, I don't know jack about coding a forum, so I don't know if this would work. Maybe expanding the folder system could be an alternative. Maybe the idea is dumb; maybe its great. Let me know what you think.

It's completely possible, and to a roundabout extent, it exists.
Not sure if you're familiar with the starred folder, but in any case, hit the checkboxes and proceed from there for moving them into the starred folder. I'd have hider'd the CS on the first message myself, but eh, can't decide another's circumstance.