By longstanding IETF precedent a charter only states the
problems that
a WG MAY solve. There is no requirement that the eventual solution
MUST meet all the criteria that might be claimed to be in the scope
of the charter.
The IETF has a longstanding precedent of having running code that
demonstrates the validity of the solution. From the Mission
Statement:
Code is only required for progress from Proposed to Draft. In this
case we already have a lot of independent code bases that more than
meet the criteria that would be applied on the Proposed to draft
transition if they were conformant.
The point of the proposed to draft transition is to define the state
to which implementations are to be expected to conform.
The rules that govern WG procedure are defined by the RFC on standards
track process, not the mission statement.
Phill