diff --git a/TODO.org b/TODO.org
index f021078d..acf95a88 100644
--- a/TODO.org
+++ b/TODO.org
@@ -652,7 +652,8 @@ it would entail =ordered?= and =equal?= and not =numeric?=, so the cast rule
 becomes a disjunction and the refusal has to name whichever the reader meant. Each
 part of that is a decision and the author has not been asked.
 
-** TODO The Ptr and union arms of the fill boundary are relaxable
+** NEXT The Ptr and union arms of the fill boundary are relaxable
+Decided 2026-09-25: relax both. A =Ptr= may be byte-filled, a poisoned pointer being the useful case, and an untagged union is filled over its whole size.
 What may be byte-filled is numbers, and structs and fixed arrays of numbers.
 A =Ptr= is refused so the rule stays one sentence, and an untagged union
 because the walk goes over a struct's fields rather than a union's members.