Reference marking on new kit

[jimgriff]

I have asked this before, but didn't really get a suitable reply.

On new kit being tested you sometimes see circular marks bisected vertically and horizontally and alternate quarters coloured in. (bit like a telescopic sight picture). I understand they are used for photographic referencing for programmes like seperation trials etc.
Does anyone know what these marks are called?
Can one buy templates for making these marks?
Are durable stickers available?

Thanks in advance.