diff --git a/03-DESIGN/01-to-be/47-milestones/G-20-lead-answers.md b/03-DESIGN/01-to-be/47-milestones/G-20-lead-answers.md
index b2631c62..77509097 100644
--- a/03-DESIGN/01-to-be/47-milestones/G-20-lead-answers.md
+++ b/03-DESIGN/01-to-be/47-milestones/G-20-lead-answers.md
@@ -207,3 +207,6 @@ names the principle that settles it, and is cited as "design 47 G A-n".
 - **A-52** (§200, §388, §614, §684, A-26; principle 7) The grants part's `view-waits` is the one its reader raises for the
   catalog half views the branch follower adopts (A-5): the part waits on the catalog half of the revision it composes
   for, through those views, and writes no `view-waits` of its own.
+- **A-53** (§681, ADR 0675; principles 3 and 7) A snapshot's record never ages out before its file: the bus module's
+  `requests` state keeps its records 91 days (one more than `snapshot-keep-days`), and the keeper removes a snapshot's
+  record together with its file at expiry, so no file is left without a record and no record without its file.