diff --git a/docs/admin/settings/settings_ai_summary.rst b/docs/admin/settings/settings_ai_summary.rst
index 4e7e33cfa..c521c2244 100644
--- a/docs/admin/settings/settings_ai_summary.rst
+++ b/docs/admin/settings/settings_ai_summary.rst
@@ -38,6 +38,24 @@ The *AI Summary* tab of the preferences is only shown when the plugin is
 activated in ``settings.yml`` (``active: true``); an instance that does not
 offer AI summaries does not show the tab at all.
 
+.. _ai_summary grounding:
+
+Grounding
+=========
+
+With ``grounding`` (the default) the query **and the top search results**
+(title, URL and snippet of at most ``max_context_items`` results) are sent to
+the LLM server; without it only the query is sent and the model answers from
+its own knowledge.  Grounded answers are more accurate and more current, at
+the cost of a longer prompt.
+
+Which data leaves the SearXNG instance therefore depends on where the LLM
+server runs: with a server on localhost or in the local network nothing leaves
+the network, with a hosted server the query and the result snippets are sent
+to that provider.  This is why the plugin is not activated by default and why
+its documentation recommends a local LLM server.  Users can opt out of
+grounding in their preferences (``ai_summary_grounding``).
+
 .. attention::
 
    A user configurable server URL allows any user of the instance to make the