Sending says (emphasis mine):
You send a short message of twenty-five words or less to a creature with which you are familiar. The creature hears the Message in its mind, recognizes you as the sender if it knows you.
Scrying says (also emphasis mine):
You can see and hear a particular creature you choose that is on the same plane of existence as you.
My question is, is there a difference between "a creature you choose" and "a creature with which you are familiar"? How familiar is familiar? It doesn't seem to require mutual familiarity, seeing how Sending implies the recipient may not know the sender.
So, for both spells, I'd ask:
- Can you target a creature you have met once but never spoken to?
- Can you target a creature you have never met, but gotten a detailed description of?
- Can you target a creature you have never met, and you only know their name?
- Can you target a creature which you can only describe in an abstract fashion (e.g. "the person who ate my pie, whoever that may be")?
I understand that this might be seen as two (or multiple) questions in one, but in my mind it's all under the umbrella of the question: How does the requirement to be "familiar" affect targeting?
My personal ruling so far was to answer the questions above with Yes/Yes/Yes/No for Scrying and Yes/Yes/No/No for Sending.