T-slot nuts

BP Widget - Panel Slot Cast Fails - UI slot panel CommScope 360G2 Fibre Patch Panel InstaPATCH 360 Modular Unloaded 4 Slot Fixed HD-1U-FX Black 1U CommScope 360G2 Fibre Patch Panel InstaPATCH slot indonesia Looks like it could be a memory slot but that couldn't be it

slot aereo panel and also for holding said bolt in a normal position of partial slot connection therewith and whose outer edge seats in an internal groove