Documentation issue: RX "rest" attribute

[moutonjr]

Hello,

I'm crushing my head to forge a YAML validating a RX schema containing this line :

        rest:
            type: //any
            of:
                - type: //arr
                  contents: //str
                - type: //map
                  values:
                      type: //any
                      of:
                          - type: //str
                          - type: //arr
                            contents: //str
                            length:
                                min: 2

Although this realluy means something I don't get yet, I can't find easy reference of rule specificication, not in https://rx.codesimply.com/, nor in this GitHub repository.

Is it possible to explain better the content of key elements in some place, for instance the exact sense of the rest keyword? (documentation issue)

Thank you,