diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index ff8e352583..c8b2646144 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -668,7 +668,7 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
         #### First, build the standard and custom-column categories ####
         for category in tb_cats.keys():
             cat = tb_cats[category]
-            if not cat['is_category'] or not cat['kind'] == 'field':
+            if not cat['is_category'] or cat['kind'] in ['user', 'search']:
                 continue
             tn = cat['table']
             categories[category] = []   #reserve the position in the ordered list
diff --git a/src/calibre/library/field_metadata.py b/src/calibre/library/field_metadata.py
index 9bd91a78b1..9d5cd4edc1 100644
--- a/src/calibre/library/field_metadata.py
+++ b/src/calibre/library/field_metadata.py
@@ -43,7 +43,8 @@ class FieldMetadata(dict):
 
     is_category: is a tag browser category. If true, then:
        table: name of the db table used to construct item list
-       column: name of the column in the connection table to join on
+       column: name of the column in the normalized table to join on
+       link_column: name of the column in the connection table to join on
        If these are None, then the category constructor must know how
        to build the item list (e.g., formats).
        The order below is the order that the categories will