According to :
Howdy all.
This Fall I'm planning on installing an exterior outlet on my in-laws
garage. The walls of the garage are finished with paneling. I would
prefer to run exposed romex just to make the job more simple. Besides,
an existing line in the garage is exposed romex that was installed by
an electrician many years ago. The exposed romex would be well above
head level and would be stapled. Can anyone forsee any problems in
doing this? I can't see any cases where the romex would be subject to
damage. As for the run down to the outlet box, the romex would be
stapled to exposed studs in that area. BTW, I'm in the U.S.

Generally speaking, both the NEC and CEC permit surface wiring
above 5' in things like basements. However, an inspector may get
considerably more picky depending on the circumstances. Eg:
wielding pieces of lumber in a garage workshop.

In garages, inspectors will go for things like "no snaggable
wire".

In my garage used as a workshop, I ran the drops to the outlets in
surface-mounted PVC conduit. Neater than MC cable. The inspector
really liked it.

The ceiling wasn't drywalled (yet), and the inspector suggested
running the cable along the bottom of the joists between the lathe
strips, and with an extra hunk of lathe to support it 1 1/2" away
from the face when crossing the lathe.
--
Chris Lewis, Una confibula non set est
It's not just anyone who gets a Starship Cruiser class named after them.