We also need to add coding standards. I think we have one about line endings already, add about supporting/stripping BOMs properly, and about making any of our own files ASCII (so charset independent). Document the new rule that we can assume any of our own files (i.e. not user-modifiable) will not need any extra checks.

Also add ones relating to #3032.

EDIT: Partly done in "Code formatting" part of codebook_standards.