diff --git a/snpdb/models/models_columns.py b/snpdb/models/models_columns.py
index 17cc76699..b27dcd0b3 100644
--- a/snpdb/models/models_columns.py
+++ b/snpdb/models/models_columns.py
@@ -28,8 +28,17 @@ class VariantGridColumn(models.Model):
     model_field = models.BooleanField(default=True)  # Standard field, can use Meta inspection to determine colmodel
     queryset_field = models.BooleanField(default=True)  # In queryset.values() (field or alias)
 
+    # These are required to be in custom columns
+    _MANDATORY_COLUMNS = {
+        "tags",
+        "tags_global",
+    }
+
     def get_css_classes(self):
         css_classes = ["user-column"]
+        if self.grid_column_name in self._MANDATORY_COLUMNS:
+            css_classes.append("mandatory")
+
         if self.annotation_level:
             annotation_level_class = ColumnAnnotationLevel(self.annotation_level).label
             css_classes.append("%s-column" % annotation_level_class.lower())
diff --git a/variantgrid/static_files/default_static/page_help/settings/view_custom_columns_help.html b/variantgrid/static_files/default_static/page_help/settings/view_custom_columns_help.html
index 0c03409e4..f42150d06 100644
--- a/variantgrid/static_files/default_static/page_help/settings/view_custom_columns_help.html
+++ b/variantgrid/static_files/default_static/page_help/settings/view_custom_columns_help.html
@@ -1,6 +1,15 @@
 Drag and drop columns to add/remove and change ordering.  
 
-The special first "variant" column is automatically created for all custom columns.
+<!--
+<h3>Mandatory columns</h3>
+<ul>
+<li><b>ID</b> - The special first "variant" column is automatically created for all custom columns.
+<li><b>Tags</b> - This is needed to add tags in an analysis
+<li><b>Tags global</b> - Shows all tags associated with a variant
+</ul>
+-->
+
+<h3>Adding / Removing columns</h3>
 
 <ul>
 <li><b>My Columns</b> - active columns. Top to bottom order is shown left to right in the grid.