diff --git a/CLAUDE.md b/CLAUDE.md
index df899df..196fc23 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -9,7 +9,7 @@ DataBuild is a bazel-based data build system. Key files:
 ## Tenets
 
 - We are building for the future, and choose to do "the right thing" rather than taking shortcuts to get unstuck. If you get stuck, pause and ask for help/input.
-
+  - In addition, do not add "unknown" results when parses or matches fail - these should always throw.
 
 ## Build & Test
 ```bash