What does "/follow" mean ?
I won't call level 35 a "Lowbie".
It's a "mid-level" in my opinion.
CC AND marking is not avery good idea, imho.
Because most people I know of interpret a marking as = "please attack !"
Marking something with the meaning of "please DO NOT attack" is something entirely unknown to me.
It's like drawing circles on a target in a bow contest (Disney's "Robin Hood", for example) with the meaning of "please do not attack !"
/follow is a chat command to follow your current target
anything <50 is a lowbie
There are multiple different marks.
Clearly most people you know have a different consensus than most of the community.
The fact that this use is unknown to you, doesn't mean it is not used that way
There is a bolt for example which I always use when there is only one mob to cc and a crosshair I use for the primary target.
But I always state "mark bolt" (or whatever symbol I used) now if the dps leaps in before I have the chance to write anything, it's his fault not mine.