在我看来，这是完全合法和可取的.我特别喜欢DELETE/notes/first的语义，但也考虑了POST/notes/first - 在第一个之前放一个新的笔记.

In my humble opinion this is perfectly legal and desirable. I especially like the semantics of DELETE /notes/first, but also consider POST /notes/first - put a new note before the first one.

在你的情况下 first 和 last 是某种特殊的魔法标识符或占位符.另一方面，有哪些替代方案?

In your case first and last are some sort of special magic identifiers or placeholders. On the other hand what are the alternatives?