docs: user names from the registry

api.md names users as the registry has them.

Auth plan M1 (docs).

1 files changed, 5 insertions, 3 deletions

diff --git a/docs/api.md b/docs/api.md
index 8c4a534..803e457 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -230,9 +230,11 @@ Load balancers can send requests to any ready node: `/ready` is the check.
 
 Every change records the node that committed it (as its Automerge author) and, for a
 write through the API, the user who wrote it (in its message, as a trailer like Git's
-`Signed-off-by:`: `User: alice`), with when (by the writer's clock). User names are
-each node's own (`--htpasswd`, or its proxy's), so who wrote it is that user at that node: `alice` on
-two nodes is one person only where their operators make it so, which nothing checks.
+`Signed-off-by:`: `User: alice`), with when (by the writer's clock). The user is a name
+in the swarm's registry ([`access.md`](access.md)), as the writing node says: nothing
+signs it, so a member could name another. In a swarm without a registry, user names
+are each node's own (`--htpasswd`, or its proxy's): `alice` on two nodes is one person
+only where their operators make it so, which nothing checks.
 `GET /admin/changes` lists them,
 newest first, with the paths each touched; `GET /admin/changes/settings` those that
 touched what is at `settings`.