Update CONTRIBUTING.md

Author: sleepyStick

CONTRIBUTING.md

@@ -440,14 +440,19 @@ If there are changes, a PR will be generated by mongodb-drivers-pr-bot.
 If any errors occurred, the PR description will display the name of the spec along
 with stderr from the `bash resync-spec.sh <spec>` command.
 
-There are three patch files that contain known test differences between
-PyMongo's tests and the specification:
-`.evergreen/patch/diff.patch`: tests where PyMongo intentionally behaves differently than the specification.
-This file should rarely be modified, as most of these represent fundamental differences in design or behavior.
-`.evergreen/patch/new.patch`: tests for new features that have not yet been implemented in PyMongo.
-Tests must be removed from this file as part of the PR that implements their feature.
-`.evergreen/patch/update.patch`: tests that have been updated in a way that causes them to fail until their
-associated driver change is implemented. Tests must be removed from this file as part of the PR that implements
+Naturally, there will be spec tests that will fail if merged since the associated fix
+or behavioral change has not been implemented yet. For existing tests that have been
+modified, we will add these changes to a patch file (in `/.evergreen/patch`). Each patch
+file will be named after a PYTHON ticket and the contents of the file will be the associated
+test differences between PyMongo's tests and the specification.
+To be clear, changes listed in these patch files will be *undone* by the script, and thus won't
+be added to pymongo.
+
+In the case that a new test is added to the spec repo (i.e., a whole new file or folder in the spec repo),
+and the associated work isn't implemented yet, we will add the test's path to
+`.evergreen/remove-unimplemented-tests.sh` along with a comment indicating the associated PYTHON ticket.
+
+These patch files and/or unimplemented paths must be removed as part of the PR that implements
 the fix or behavioral change.
 
 #### Adding to a patch file