diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index 7b8aafa15b..03f8b1b655 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -194,6 +194,15 @@ in the QEMU object model anymore. ``power5+``, ``power5+_v2.1``,
 an alias, but for consistency these will get removed in a future
 release, too. Use ``power5p_v2.1`` and ``power7p_v2.1`` instead.
 
+``Sun-UltraSparc-IIIi+`` and ``Sun-UltraSparc-IV+`` CPU names (since 9.1)
+'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+The character "+" in device (and thus also CPU) names is not allowed
+in the QEMU object model anymore. ``Sun-UltraSparc-IIIi+`` and
+``Sun-UltraSparc-IV+`` are currently still supported via a workaround,
+but for consistency these will get removed in a future release, too.
+Use ``Sun-UltraSparc-IIIi-plus`` and ``Sun-UltraSparc-IV-plus`` instead.
+
 CRIS CPU architecture (since 9.0)
 '''''''''''''''''''''''''''''''''