Change the wording on branch feature freeze

PROCESS.md

@@ -74,12 +74,11 @@ star, smile, etc.). Some good tips about code reviews can be found in our
 
 ## Feature freeze on the 7th for the release on the 22nd
 
-After 7th at 23:59 (Pacific Time Zone) of each month, RC1 of the upcoming
-release (to be shipped on the 22nd) is created and deployed to GitLab.com. 
-The stable branch for this release is frozen, which means master is no longer
-merged into it. Release managers can decide to include the last known green 
-pipeline as a last item going to a stable branch, regardless of whether 
-the feature freeze time has passed.  
+After 7th at 23:59 (Pacific Time Zone) of each month, stable branch and RC1 
+of the upcoming release (to be shipped on the 22nd) is created and deployed to GitLab.com. 
+The stable branch is frozen at the most recent "qualifying commit" on master.
+A "qualifying commit" is one that is pushed before the feature freeze cutoff time
+and that passes all CI jobs (green pipeline).
 
 Merge requests may still be merged into master during this
 period, but they will go into the _next_ release, unless they are manually