As an instructor, I would personally write somewhere near the logbook entry; "[pilot name] has satisfactorily demonstrated competency in flying the [aircraft type].[my name/licence number][date]".
But at the end of the day, the specific wording doesn't matter. And if your logbook doesn't have a specific place for the sign off, then you probably don't require the type rating for Botswana and therefore the wording matters even less.