Make explicit that the CLC votes on implementation not design.

Also minor clarifications on the scope of base changes.

Author: AndreasPK

PROPOSALS.md

@@ -120,7 +120,7 @@ The following is a step by step guide for common proposals:
 If your proposal is a "multi-phase proposal" with multiple implementation and deprecation steps, make sure to
 precisely define when each step is supposed to take place.
 
-### A note on stale proposals
+### Stale proposals
 
 The CLC can revoke its approval for a proposal if an **"activity"** has been overdue for over a year. The revocation request, which
 explains what has changed with the passage of time to justify the review, can be initiated by the chair. If no CLC member vetos
@@ -131,6 +131,15 @@ the request, then it automatically passes.
 - for a simple proposal: whether it has been merged
 - for a multi-phase proposal: whether the next step has been carried out as planned
 
+### `base` changes
+
+Any GHC MR that changes a part of base under CLC purview requires a CLC proposal, pointing to the GHC MR, seeking approval from CLC of the changes to the base API.
+This specifically includes:
+
+* Bug-fixes that make a wrongly-implemented functions obey their specification.
+  Even if the change clearly fixes an outright bug.
+* Performance improvements -- even if performance always improves.
+
 ## The "when"
 
 If you've got a pet issue that's been sleeping in the depths of a mailing list

README.md

@@ -41,7 +41,9 @@ core-libraries-committee at haskell dot org
 ## `base` package
 
 The primary responsibility of CLC is to manage API changes of `base` package. The ownership of `base` belongs to GHC developers, and they can maintain it freely without CLC involvement as long as changes are invisible to clients. Changes which affect performance or laziness and similar are deemed visible. Documentation changes normally fall under GHC developers purview, except significant ones (e. g., adding or changing type class laws).
+
 Proposals to change the API of the `base` package are managed by the process, described in [`PROPOSALS.md`][proposals].
+While design discussions and questions are welcome, the CLC will only vote on proposals that are accompanied by a concrete implementation (merge request)."
 
 [proposals]: https://github.com/haskell/core-libraries-committee/blob/main/PROPOSALS.md