フリー問題

問題文

Two systems exchange entity references over an interface. What form does the documentation say those references should take when they are passed between systems?

選択肢

1. The shortest form that resolves, because the receiver can always fill in the missing parts.
2. The automatically generated identifier of the entity.
3. The verbose object form with one field per part.
4. Complete references with all three parts, lowercased by the sender and read case insensitively by the receiver.