diff --git a/src/math/categories.pysty3 b/src/math/categories.pysty3
index d18c484..075ff84 100644
--- a/src/math/categories.pysty3
+++ b/src/math/categories.pysty3
@@ -142,3 +142,11 @@ __HEADER__(Definitions of categories with automatic indexing)%% Wrapper commands
   [
     \translate{GrAb~(Category~description)}
   ]
+\DeclareCategory
+  [
+    operator = \operatorname,
+    formula = \Delta,
+    ordered = Ordinal,
+    description = \translate{Ordinal ~ number ~ category ~ (Category ~ description)}
+  ]
+  {OrdCat}
diff --git a/src/utils/mathematical-categories.pydict b/src/utils/mathematical-categories.pydict
index fff8aa8..85a2403 100644
--- a/src/utils/mathematical-categories.pydict
+++ b/src/utils/mathematical-categories.pydict
@@ -16,3 +16,4 @@ Field (Category description),Fields and field extensions,Körper und Körpererwe
 AffVar (Category description),Affine Varieties over $k$,Affine Varietäten über $k$
 Sch (Category description),Schemes and homomorphisms,Schemata und Homomorphismen
 GrAb (Category description),Graded abelian groups and homomorphisms,Graduierte Gruppen und Homomorphismen
+Ordinal number category (Category description),Finite ordinal numbers and order-preserving maps,Endliche Ordinalzahlen und ordnungserhaltende Abbildungen