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 02c7c60d..d015e5d3 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
@@ -336,3 +336,6 @@ names the principle that settles it, and is cited as "design 47 G A-n".
   it keeps the trunk's: objects `branch.<branch>.<n>` (the branch escaped as a name) beside `trunk.<n>`, the trunk being
   the first watched branch's; the branch follower's per-branch `revision` reads them, and `BuildEdges.fp` is the entry's
   fingerprint in the revision whose `source` the build names.
+- **A-86** (§354, §375; principle 7) `KeepInput` is called by the indexer's own `input` verb, when a run on request's asker
+  hands an input; the indexer asks no `run` itself. A kind-3 edge's language is its catalog edge's target artifact's
+  language, else the one language the entry's artifacts share, as built in mesh-delivery 652285f0.