Meaning of symbols engravings in case

Niad lock case.

special threading to make sure the caseback always aligns correctly

I noticed my Snoopy 50th has this symbol, and no other engraving on the caseback since it doesnt fit.

Oh lol, I guess I missed it since its not filled in with black paint like the other engravings.

Hmm then maybe the marking is so people (watchmakers during servicing) know exactly where to line up the case back during reassembly when its not obvious what orientation the back should be?

I'm assuming the NAIAD can lock into place in more than one orientation. Like exactly at 0, 90, 180 and 270 degrees (just an example, I have no idea). Its obvious on stuff like solid case backs with an engraved medallion, less obvious on display case backs with just lettering on the edge.

My titanium ultradeep doesn't have the marking on the case. Haven't checked all the others yet but this is interesting.

I do believe it’s the start point for Niad lock to ensure things line up correctly.