Still, I'm not entirely satisfied with my understanding of things.
At Tacoma I have the 122nd USAAF Base Force (ENG-unit) attached to West Coast HQ, which is a Static restricted HQ. This unit has an [S] behind its name when I hover over it, which I assume means that it too is static restricted.
Also at Tacoma, I have the 144th FA Rgt (ART-unit) attached to West Coast HQ. This unit has a [S] and a [R] behind its name, which I'm assuming means Static restriced AND Restricted (Temp or Perm). Why would a Static restricted unit have an additional restriction?
Another unit at Tacoma is the 3rd Infantry Division. Again attached to West Coast HQ, and has an [S] behind its name. No [R] in sight on this one.
Yet another unit here is the 41st Infantry Division, also attached to West Coast HQ, but is unrestricted (no letters at all behind the unit's name and I can change it's HQ).
The two ARM-units at Tacoma have both got [S] and [R]. Still attached to West Coast HQ.
So, 2 questions here. Why has the 41st Infantry Division not inherited the restrictions of its HQ unit? And why does some of the units with [S] (which I'm assuming means Static Restricted) also have [R], while others don't? As far as I can tell from your post, a permanent or temporary restriction on an already static restricted unit doesn't add any constraints.