Document why auth providers aren't validated in the admin API. (#12004)

Since it is reasonable to give a future or past auth provider,
which might not be in the current configuration.

1 files changed, 2 insertions, 1 deletions

diff --git a/docs/admin_api/user_admin_api.md b/docs/admin_api/user_admin_api.md

index 1bbe237080..4076fcab65 100644
--- a/docs/admin_api/user_admin_api.md
+++ b/docs/admin_api/user_admin_api.md
@@ -126,7 +126,8 @@ Body parameters:
   [Sample Configuration File](../usage/configuration/homeserver_sample_config.html)
   section `sso` and `oidc_providers`.
   - `auth_provider` - string. ID of the external identity provider. Value of `idp_id`
-    in homeserver configuration.
+    in the homeserver configuration. Note that no error is raised if the provided
+    value is not in the homeserver configuration.
   - `external_id` - string, user ID in the external identity provider.
 - `avatar_url` - string, optional, must be a
   [MXC URI](https://matrix.org/docs/spec/client_server/r0.6.0#matrix-content-mxc-uris).