I might be wrong, but as I read the OP he more wants/expects "mark" as an ability
- Not everybody can do
- Not something you do all the time
(take your pick)
As in, either it's a special feature only few can do (a new fighter subclass perhaps) but then do all the time (or as much as the rules allow, there can be limitations) or, if it's something everyone can do, marking comes with disadvantages so you only do it sometimes but not always.
The DMG variant, however, isn't either of these. Despite being called marking, it's not what that term used to mean; it's more like a general damage bonus to add stickiness.