diff --git a/rt-doc-type-old.yml b/rt-doc-type-old.yml
index f493540..d4ef6c0 100644
--- a/rt-doc-type-old.yml
+++ b/rt-doc-type-old.yml
@@ -11,6 +11,9 @@ components:
           properties:
             OneCandidate:
               $ref: "#/components/schemas/OneCandidate"
+            XML_buffer:
+              type: string
+              readOnly: true
         - $ref: "./rt.yml#/components/schemas/ResultItem"
 
     DocumentTypesCandidatesResult: