diff --git a/src/MDDataHistorySubjectsSet.php b/src/MDDataHistorySubjectsSet.php
index 730820e..9ce92dc 100644
--- a/src/MDDataHistorySubjectsSet.php
+++ b/src/MDDataHistorySubjectsSet.php
@@ -1,6 +1,7 @@
 <?PHP
 /**
  * Contains a class for controlling the list of available subjects for data history writing.
+ * Deprecated: Replaced by MusdbBaseEntry in musdb.
  *
  * @author Joshua Ramon Enslin <joshua@museum-digital.de>
  */
@@ -22,7 +23,6 @@ final class MDDataHistorySubjectsSet extends MDValueSet {
         'object',
         'podcast',
         'podcast_episode',
-        'sammlung',
         'series',
         'user',
     ];