Non-binary fractional circular primitives

[Chris Dee]

 I'd personally be happy to explicitly state that combining circular primitives with non 90 degree angles (for example 1-16 and 1-8) is forbidden in official parts (due to point 3 above).

So would I.

I guess we could add a 'Primitives Regulations' section to the LDraw.org Official Parts Library Specifications, but there is quite a lot to document.