Ensures the right type is tracked for links ensures relations are removed.

src/Umbraco.Core/Constants-Conventions.cs

@@ -358,6 +358,15 @@ namespace Umbraco.Core
                 /// </summary>
                 public const string RelateParentMediaFolderOnDeleteAlias = "relateParentMediaFolderOnDelete";
 
+                /// <summary>
+                /// Returns the types of relations that are automatically tracked
+                /// </summary>
+                /// <remarks>
+                /// Developers should not manually use these relation types since they will all be cleared whenever an entity
+                /// (content, media or member) is saved since they are auto-populated based on property values.
+                /// </remarks>
+                public static string[] AutomaticRelationTypes = new[] { RelatedMediaAlias, RelatedDocumentAlias };
+
                 //TODO: return a list of built in types so we can use that to prevent deletion in the uI
             }
         }

src/Umbraco.Core/Persistence/Repositories/Implement/ContentRepositoryBase.cs

@@ -837,11 +837,10 @@ namespace Umbraco.Core.Persistence.Repositories.Implement
                 trackedRelations.AddRange(refs);
             }
 
-            if (trackedRelations.Count == 0) return;
+            //First delete all auto-relations for this entity
+            RelationRepository.DeleteByParent(entity.Id, Constants.Conventions.RelationTypes.AutomaticRelationTypes);
 
-            //First delete all relations for this entity
-            var relationTypes = trackedRelations.Select(x => x.RelationTypeAlias).ToArray();
-            RelationRepository.DeleteByParent(entity.Id, relationTypes);
+            if (trackedRelations.Count == 0) return;
 
             var udiToGuids = trackedRelations.Select(x => x.Udi as GuidUdi)
                 .ToDictionary(x => (Udi)x, x => x.Guid);

src/Umbraco.Web/PropertyEditors/RichTextPropertyEditor.cs

@@ -144,7 +144,7 @@ namespace Umbraco.Web.PropertyEditors
                     yield return new UmbracoEntityReference(udi, Constants.Conventions.RelationTypes.RelatedMediaAlias);
 
                 foreach (var udi in _localLinkParser.FindUdisFromLocalLinks(asString))
-                    yield return new UmbracoEntityReference(udi, Constants.Conventions.RelationTypes.RelatedMediaAlias);
+                    yield return new UmbracoEntityReference(udi, Constants.Conventions.RelationTypes.RelatedDocumentAlias);
 
                 //TODO: Detect Macros too ... but we can save that for a later date, right now need to do media refs
             }