diff --git a/src/ifctester/ifctester/ids.py b/src/ifctester/ifctester/ids.py
index 24bed309b8..0071f48fb6 100644
--- a/src/ifctester/ifctester/ids.py
+++ b/src/ifctester/ifctester/ids.py
@@ -171,8 +171,8 @@ class Specification:
         self.minOccurs = ids_dict["@minOccurs"]
         self.maxOccurs = ids_dict["@maxOccurs"]
         self.ifcVersion = ids_dict["@ifcVersion"]
-        self.applicability = self.parse_clause(ids_dict["applicability"])
-        self.requirements = self.parse_clause(ids_dict["requirements"])
+        self.applicability = self.parse_clause(ids_dict["applicability"]) if "applicability" in ids_dict else []
+        self.requirements = self.parse_clause(ids_dict["requirements"]) if "requirements" in ids_dict else []
         return self
 
     def parse_clause(self, clause):
@@ -201,14 +201,16 @@ class Specification:
             return
 
         elements = []
-        for i, facet in enumerate(self.applicability):
-            # Usually, we rely on an entity applicability to give us our first
-            # shortlist of elements, as it's the most efficient way to filter
-            # elements. If this does not exist, then we have no choice but to
-            # check everything.
-            if i == 0 and not isinstance(facet, Entity):
-                elements = list(ifc_file)
-            elements = facet.filter(ifc_file, elements)
+        
+        if self.applicability:
+            for i, facet in enumerate(self.applicability):
+                # Usually, we rely on an entity applicability to give us our first
+                # shortlist of elements, as it's the most efficient way to filter
+                # elements. If this does not exist, then we have no choice but to
+                # check everything.
+                if i == 0 and not isinstance(facet, Entity):
+                    elements = list(ifc_file)
+                elements = facet.filter(ifc_file, elements)
 
         for element in elements:
             is_applicable = True
@@ -237,6 +239,7 @@ class Specification:
                 facet.status = bool(facet.failed_entities)
 
         self.status = True
+        # if spec is required
         if self.minOccurs != 0:
             if not self.applicable_entities:
                 self.status = False
@@ -244,11 +247,15 @@ class Specification:
                     facet.status = False
             elif self.failed_entities:
                 self.status = False
-        elif self.minOccurs == 0 and self.maxOccurs != 0:
+        # if spec is optional
+        elif self.minOccurs == 0 and self.maxOccurs != 0: 
             if self.failed_entities:
                 self.status = False
+        # if spec is prohibited
         elif self.maxOccurs == 0:
-            if (len(self.applicable_entities) - len(self.failed_entities)) > 0:
+            if (len(self.applicable_entities)) > 0 and len(self.requirements) == 0:
+                self.status = False
+            if (len(self.applicable_entities)) > 0 and (len(self.applicable_entities) - len(self.failed_entities)) > 0:
                 self.status = False
 
     def get_usage(self):
diff --git a/src/ifctester/test/test_ids.py b/src/ifctester/test/test_ids.py
index 6a4eeef436..2bdcde22f2 100644
--- a/src/ifctester/test/test_ids.py
+++ b/src/ifctester/test/test_ids.py
@@ -250,3 +250,43 @@ class TestSpecification:
             "applicability": {},
             "requirements": {},
         }
+    
+    def test_specification_has_no_requirements(self):
+        model = ifcopenshell.file()
+        wall = model.createIfcWall()
+        waldo = model.createIfcWall(Name="Waldo")
+        
+        test_ids = ids.Ids(title="Title")
+        spec = ids.Specification(name="Name")
+        spec.applicability.append(ids.Entity(name="IFCWALL"))
+        test_ids.specifications.append(spec)
+        spec.minOccurs = 1
+        run("A specification that is required and has at least one applicable entity but no requirements shall pass", test_ids, model, True, [wall, waldo], None)
+        
+        test_ids = ids.Ids(title="Title")
+        spec = ids.Specification(name="Name")
+        test_ids.specifications.append(spec)
+        spec.minOccurs = 1
+        run("A specification that is required but has no applicable entities or requirements shall fail", test_ids, model, False, None, None)
+        
+        test_ids = ids.Ids(title="Title")
+        spec = ids.Specification(name="Name")
+        spec.applicability.append(ids.Entity(name="IFCWALL"))
+        test_ids.specifications.append(spec)
+        spec.minOccurs = 0
+        run("A specification that is optional and has at least one applicable entity but no requirements shall pass", test_ids, model, True, [wall, waldo], None)
+        
+        test_ids = ids.Ids(title="Title")
+        spec = ids.Specification(name="Name")
+        spec.applicability.append(ids.Entity(name="IFCWALL"))
+        test_ids.specifications.append(spec)
+        spec.minOccurs = 0
+        spec.maxOccurs = 0
+        run("A specification that is prohibited and has at least one applicable entity but no requirements shall fail", test_ids, model, False, [wall, waldo], None)
+        
+        test_ids = ids.Ids(title="Title")
+        spec = ids.Specification(name="Name")
+        test_ids.specifications.append(spec)
+        spec.minOccurs = 0
+        spec.maxOccurs = 0
+        run("A specification that is prohibited but has no applicable entities or requirements shall pass", test_ids, model, True, None, None)