Node IPLD specification is incorrect and incomplete

[str4d]

https://atproto.com/specs/repository#mst-structure

https://github.com/bluesky-social/atproto-website/blob/4744a24acafa87d42b5e352f5af69a3b6b4684a3/content/specs/repository.md?plain=1#L85-L92

The v field is documented as:

• ✅ A CID link.
• ✅ Required.
• ⚠️ A link to a sub-tree Node.

After experimenting with my own repository's CAR, I've concluded that this is most likely an accidental merge of two separate fields:

• v:
  • A CID link.
  • Required.
  • A link to the Lexicon value corresponding to this TreeEntry's key.
• t:
  • A CID link.
  • Optional (CID link || null).
  • A link to a sub-tree Node.