explain proposal neutrality

specification/proposals_intro.rst

@@ -21,6 +21,10 @@ The process for submitting a Matrix Spec Change (MSC) Proposal is as follows:
 
 Final decisions on review are made by the +matrix:matrix.org community (i.e. the core team), acting on behalf of the whole Matrix community.
 
+Proposals **must** act to the greater benefit of the entire Matrix ecosystem, rather than benefiting or privileging any single player or subset of players - and must not contain any patent encumbered IP.  The Matrix core team pledges to act as a neutral custodian for Matrix on behalf of the whole ecosystem.
+
+The directions above are intended to be short, simple and pragmatic - although a full governance document for the Matrix core team will follow in due course.
+
 The process for handling proposals is described in the following diagram. Note that the lifetime of a proposal is tracked through the corresponding labels for each stage in the `matrix-doc issue tracker <https://github.com/matrix-org/matrix-doc/issues>`_.
 
 ::