diff --git a/core/src/main/java/org/polypheny/db/algebra/polyalg/PolyAlgDeclaration.java b/core/src/main/java/org/polypheny/db/algebra/polyalg/PolyAlgDeclaration.java
index 65df942332..d1109c1e47 100644
--- a/core/src/main/java/org/polypheny/db/algebra/polyalg/PolyAlgDeclaration.java
+++ b/core/src/main/java/org/polypheny/db/algebra/polyalg/PolyAlgDeclaration.java
@@ -167,6 +167,9 @@ private static boolean hasRequiredTags( ImmutableList<Parameter> params ) {
             if ( p.requiresAlias && !p.tags.contains( ParamTag.ALIAS ) ) {
                 return false;
             }
+            if (p.tags.contains( ParamTag.HIDE_TRIVIAL ) && ! p.tags.contains( ParamTag.ALIAS ) ) {
+                return false;
+            }
         }
         return true;
     }
@@ -423,7 +426,12 @@ public enum ParamTag {
         /**
          * Indicates that negative values are not permitted (typically together with IntArg)
          */
-        NON_NEGATIVE
+        NON_NEGATIVE,
+
+        /**
+         * For projects and some other operators it is useful to let the user hide any trivial arguments in the UI
+         */
+        HIDE_TRIVIAL
     }
 
 }
diff --git a/core/src/main/java/org/polypheny/db/algebra/polyalg/PolyAlgRegistry.java b/core/src/main/java/org/polypheny/db/algebra/polyalg/PolyAlgRegistry.java
index 945edae476..399d03031d 100644
--- a/core/src/main/java/org/polypheny/db/algebra/polyalg/PolyAlgRegistry.java
+++ b/core/src/main/java/org/polypheny/db/algebra/polyalg/PolyAlgRegistry.java
@@ -92,7 +92,7 @@ private static void populateDeclarationsMap() {
         declarations.put( LogicalRelProject.class, PolyAlgDeclaration.builder()
                 .creator( LogicalRelProject::create ).model( DataModel.RELATIONAL )
                 .opName( "PROJECT" ).opAliases( List.of( "P", "PROJECT#" ) ).numInputs( 1 ).opTags( logTags )
-                .param( Parameter.builder().name( "projects" ).tag( ParamTag.ALIAS ).isMultiValued( true ).type( ParamType.REX ).build() )
+                .param( Parameter.builder().name( "projects" ).tags( List.of(ParamTag.ALIAS, ParamTag.HIDE_TRIVIAL ) ).isMultiValued( true ).type( ParamType.REX ).build() )
                 .build() );
         declarations.put( LogicalRelScan.class, PolyAlgDeclaration.builder()
                 .creator( LogicalRelScan::create ).model( DataModel.RELATIONAL )