This is a general checklist that will help to avoid extended discussion during the document review and approval process. The IESG has compiled a more detailed list of useful topics to consider.
Verify that all user-visible text fields are internationalizable; see RFC 2277. For most cases, this means UTF-8
If text fields are included in some calculations, like matching, sorting, etc., verify that how those operations are applied to the Unicode/ISO 10646 character set are described in detail. See stringprep