In relation to my question on Usage of 'z' in the word serialized in English?, it seems I was mistaken in assuming there is a generally accepted correct variant of English.
The question Which variant of English should I use when my target audience is the world? addresses the issue of what to be aware of when writing for a global audience, and the answers focuses mostly on which kind of words and expressions to use (and not use).
I am interested in which grammar to follow when writing for a global audience?
Specifically which rulebook on grammar and which dictionary should I follow?