In component condition, there are two strings, addcompletions and addgrades, which use placeholder - {no}. It is the first time I meet placeholder like this. I'm afraid that it should be {$a->no}. Any one can comfirm it?
Thanks for raising this. The placeholder {no} is quite rare and it is used by Moodle forms library for repeating elements. It is replaced with the number when displaying - for example "Add 3 activity conditions to form" (you may know the similar string from a question editing form).
So please, just leave it {no} as it is.
Oh, that's funny! Thanks for reply.