hmm... well in this case I branched of master... so do I branch off develop to create the docs or what?
Yes this is another (small) interim period where things are a little more fiddly than I'd like - sorry about that. We're about to freeze 6.1 for release (branching for regression fixes on a release-6.1 branch) so the 'is ascii' operator you've done will merge into the next release... Therefore, there's no harm in you merging develop into your branch as it stands now as that will be 'master' within a week or so (all being well).
Edit: I'll try and squeeze it into 6.1 if you don't mind getting a doc/release note added asap