diff --git a/CONVENTIONS.md b/CONVENTIONS.md
index a8401c1..7fc9a32 100644
--- a/CONVENTIONS.md
+++ b/CONVENTIONS.md
@@ -1,3 +1,10 @@
+# Conventions
+
+When contributing code to this project, you MUST follow the requirements
+specified here.
+
+## Code Conventions
+
 When contributing code to this project, you MUST follow these principles:
 
 - Code should be easy to read and understand.
@@ -13,3 +20,13 @@ When contributing code to this project, you MUST follow these principles:
 - Documentation should document semantics, not syntax.
 - Prefer importing modules, not individual items from modules.
 - Do not use f-strings in logging statements.
+- Loop variables and walrus-expression-variables should be deleted when
+  unneeded to keep scope clean, and to avoid accidental use.
+
+## Testing
+
+When contributing test to this project, you MUST follow these principles:
+
+- Do not use any testing libraries other than `pytest`.
+- Mocking is the root of all evil. Writing your own stubs is much more
+  preferable.