Define protocol version and expected lifecycle with browsers

[colinbendell]

The protocol version in the key-commitment example specifies that the value should be PrivateStateTokenV3VOPRF. However, in the current version of Chrome the value is V1 (PrivateStateTokenV1VOPRF). What is the expected naming convention for this field? Should it be a structured header with the version as a numeric field? Since PrivateStateTokenV3VOPRF was already in the wild, will we expect PrivateStateTokenV3VOPRF to be skipped in the future? Is there an expectation of major and minor versions for compatibility?

I could imagine this field being more structured and mirror the sec-ch-ua:
Sec-Private-State-Token-Crypto-Version: "VOPRF";v="1"