Face Mill Insert Question

[ImanCarrot]

I'm tooling up for a job that needs a Face Mill operation.

I've only used one once before so I thought I'd replace the carbide inserts.

I thought that since each insert has four cutting faces I'd scribe on the back 1, 2, 3, 4 so I knew which face was worn after machining.

However, I noted that there's already a 1, 2, 3 and 4 marked on the corners of the inserts.

What is the convention please, does the 1 on the corner of the first cutting surface point to the centre of the face mill or does it point to the outside?

There's no- one I can ask here. I specialise in diamond machining, not conventional machining, so any help will be gratefully appreciated. I like doing things right

Thanks in advance.

PS- the inserts are about 1/2" square, 1/8" thick. There's three of them, the total outer diameter of the cutter is 2" if that helps.

[ImanCarrot]

Sod it, I'll put the corner "1's" facing the spindle centre. If that ain't right conventionaly then it is now, in my shop.