guidance on writing libraries for instance mode

[lmccart]

Posting this from an email I received:

My library currently breaks when used in instance mode. I can see why, because I have explicit calls to core p5 functions, but I don't know how to fix it.

Could something be added to the creating libraries page about what else is required from a library so that it works in instance mode too? I have looked at some of the other libraries available and they either don't support instance mode either or use a bespoke organisation, so it's difficult to figure out what a standard is. There is a brief not about the fact that both exist but only about not polluting the global namespace.