diff --git a/Collection-Storage.md b/Collection-Storage.md
index 297b278..c456cce 100644
--- a/Collection-Storage.md
+++ b/Collection-Storage.md
@@ -95,6 +95,8 @@ jq .  .Radicale.props
 
 Since 3.3.2 the item cache can be located outside by option `[storage] use_cache_subfolder_for_item = True`
 
+Since 3.3.2 the item cache format can be toggled between SHA-256 or using mtime+size of original item by option `[storage] use_mtime_and_size_for_item_cache = True` (recommend to use only on systems where mtime has "ns" granularity)
+
 ```
 [d] /var
 └─[d] /lib