diff --git a/docs/formats/core-data-regions.md b/docs/formats/core-data-regions.md
index 3a8c5d2..d137049 100644
--- a/docs/formats/core-data-regions.md
+++ b/docs/formats/core-data-regions.md
@@ -168,3 +168,20 @@ entries mean, what 148 refers to, and why there are ten, are all unestablished.
 Ten does not match any count already known for this level -- 238 moby
 classes, 74 tie, 7 shrub, 93 tfrag textures -- so this is not yet tied to any
 structure elsewhere in the lump.
+
+### Follow-up: the 148 stride is a coincidence
+
+Treating the ten entries' low halves as offsets from the region start lands on
+blocks exactly 148 bytes apart, the first nine of which begin `08 00` followed
+by a 16-bit id stepping by 0x40. That is a convincing-looking structure and it
+does not survive being extended: walking the same 148-byte stride across the
+rest of the region, **only 14 of 4657 blocks** start with `08 00`. The first
+nine agree and then the pattern breaks.
+
+So the ten entries are not a pointer table. The constant stride held for
+eight consecutive values, which is far more than chance should produce and far
+less than a structure needs.
+
+Recorded because the lead was committed as a lead and this is where it goes.
+Nothing else about the region has been identified: it is real, non-zero data
+of unknown type, bounded, and unopened beyond these ~150 bytes.