From 44f0d573cf57772b7f53e918d0c3580cba4fde32 Mon Sep 17 00:00:00 2001
From: Dirk Klimpel <5740567+dklimpel@users.noreply.github.com>
Date: Fri, 28 Oct 2022 14:55:03 +0200
Subject: [PATCH] Add docs for an empty `trusted_key_servers` config option
 (#13999)

* Add docs for an empty `trusted_key_servers` config option

* small rewording

* Tweak changelog
---
 changelog.d/13999.doc                            | 1 +
 docs/usage/configuration/config_documentation.md | 6 ++++++
 2 files changed, 7 insertions(+)
 create mode 100644 changelog.d/13999.doc

diff --git a/changelog.d/13999.doc b/changelog.d/13999.doc
new file mode 100644
index 0000000000..26538049e4
--- /dev/null
+++ b/changelog.d/13999.doc
@@ -0,0 +1 @@
+Explain how to disable the use of `trusted_key_servers`.
\ No newline at end of file
diff --git a/docs/usage/configuration/config_documentation.md b/docs/usage/configuration/config_documentation.md
index fb5eb42c52..97fb505a5f 100644
--- a/docs/usage/configuration/config_documentation.md
+++ b/docs/usage/configuration/config_documentation.md
@@ -2681,6 +2681,12 @@ is still supported for backwards-compatibility, but it is deprecated.
 warning on start-up. To suppress this warning, set
 `suppress_key_server_warning` to true.
 
+If the use of a trusted key server has to be deactivated, e.g. in a private
+federation or for privacy reasons, this can be realised by setting
+an empty array (`trusted_key_servers: []`). Then Synapse will request the keys
+directly from the server that owns the keys. If Synapse does not get keys directly
+from the server, the events of this server will be rejected.
+
 Options for each entry in the list include:
 * `server_name`: the name of the server. Required.
 * `verify_keys`: an optional map from key id to base64-encoded public key.