Possibly understanding something is better than merely knowing it

That's interesting, shona - think I might have placed those the other way around. I might understand French moderately well, but I would hesitate to claim knowledge of French, unless it was suitably qualified by limited ! I guess this a symptom of reading knowledge as a definitive statement unless hedged, whereas the full flavour of (true) understanding has been debased in modern currency to a more temporising quality -
"I understand what you're getting at..." (meaning actually 'I have processed the sounds issuing from your lips') "but I can't fully agree with that position" (meaning actually 'but I have not deviated from my preconceptions one iota!') I think this also underscores a difference between 'knowing', and 'knowing of', something.

How about to 'be informed' about something?