I recently setup my own CalDAV and CardDAV server (using Radicale  and I wondered how I can send and receive objects from this server (implementation). This journey let me read the   CardDAV RFC ( I want to practice implementing RFCs, since I hav e never done that before. It looks like the CardDAV one is quite big (?) for the first try.So I wondered: Do you recommend or know a RFC which is easy/small to implement so I can get my feet wet?