diff --git a/object/service.proto b/object/service.proto
index 4cf2aa2..cf550fe 100644
--- a/object/service.proto
+++ b/object/service.proto
@@ -318,6 +318,8 @@ message SearchRequest {
     //   object_type
     // * $Object:homomorphicHash \
     //   homomorphic_hash
+    // * $Object:split.parent \
+    //   object_id of parent
     //
     // There are some well-known filter aliases to match objects by certain
     // properties:
@@ -328,11 +330,10 @@ message SearchRequest {
     // * $Object:LEAF \
     //   With the `value` set to `true` checks if an object is a leaf in a split
     //   hierarchy. With other values returns non-leaf objects.
-    // * $Object:PARENT \
-    //   With the `value` set to `true` checks if an object has any child
-    //   objects is `Split` header or there are objects known to reference this
-    //   object as a parent. If set to `false` returns object without child
-    //   objects in `Split` header or any objects known to reference them.
+    // * $Object:CHILDFREE \
+    //   With the `value` set to `true` checks if an object has empty
+    //   children list in `Split` header. With other values returns
+    //   non-childfree objects.
     message Filter {
       // Match type to use
       MatchType match_type = 1;
diff --git a/proto-docs/object.md b/proto-docs/object.md
index d420338..4072fa4 100644
--- a/proto-docs/object.md
+++ b/proto-docs/object.md
@@ -565,6 +565,8 @@ prefix to the name. Here is the list of fields available via this prefix:
   object_type
 * $Object:homomorphicHash \
   homomorphic_hash
+* $Object:split.parent \
+  object_id of parent
 
 There are some well-known filter aliases to match objects by certain
 properties:
@@ -575,11 +577,10 @@ properties:
 * $Object:LEAF \
   With the `value` set to `true` checks if an object is a leaf in a split
   hierarchy. With other values returns non-leaf objects.
-* $Object:PARENT \
-  With the `value` set to `true` checks if an object has any child
-  objects is `Split` header or there are objects known to reference this
-  object as a parent. If set to `false` returns object without child
-  objects in `Split` header or any objects known to reference them.
+* $Object:CHILDFREE \
+  With the `value` set to `true` checks if an object has empty
+  children list in `Split` header. With other values returns
+  non-childfree objects.
 
 
 | Field | Type | Label | Description |