[rkagerer]

The alliance will develop written specifications detailing the features of OpenUSD

Since its an existing standard hasn't this already been done, at least to a decent extent?

[dagmx]

No, there is an implementation but not a formal specification.

Albeit parts of the implementation are well defined enough that they are a good basis for a specification, many behaviour specifics are only existent in code.

A specification would need to be implementation independent.