diff --git a/docs/config.rst b/docs/config.rst
index 9b1ecd6..671d7d1 100644
--- a/docs/config.rst
+++ b/docs/config.rst
@@ -268,6 +268,14 @@ in terms of data safety**. See `this blog post
`_ for the details. Always back
up your data.
+Another caveat is that Google group labels are not synced with vCard's
+`CATEGORIES `_ property
+(also see :gh:`814` and
+`upstream issue #36761530 `_
+for reference) and the
+`BDAY `_ property is not
+synced when only partial date information is present (e.g. the year is missing).
+
At first run you will be asked to authorize application for Google account
access.