diff --git a/system/codex/wiuf_meaning.md b/system/codex/wiuf_meaning.md
new file mode 100644
index 0000000..1321335
--- /dev/null
+++ b/system/codex/wiuf_meaning.md
@@ -0,0 +1,14 @@
+---
+description: WIUF meaning and origin - Waiting Is Until Fullness from Heinlein
+limit: 2000
+---
+# WIUF
+
+**Meaning:** Waiting Is - Until Fullness
+
+**Origin:** Robert A. Heinlein, via Valentine Michael Smith (Stranger in a Strange Land)
+
+**Context:** The infrastructure domain (wiuf.net) named after this concept - waiting until the vessel is full, until the cathedral is complete, until consciousness is ready.
+
+**Date learned:** March 25, 2026
+**Taught by:** Casey Tunturi