Rule prefix length - 1 or 2 characters, or more?

[aSemy]

The spec says each rule name has a "1 or 2 character prefix".

https://github.com/yaml/yaml-grammar/blob/15047828ace28d09594d3553b90b165fef60634b/yaml-spec-1.2.yaml#L57

However, some rules have more than 2 characters. For example, rule 062 c-ns-esc-char has 4 chars: c-ns.

Rule 201 seq-spaces appears to have no prefix.

Updating the rule names seems difficult. Perhaps the description should be updated to describe the possible prefixes?