diff --git a/doc/v2/_static/petab_schema_v2.yaml b/doc/v2/_static/petab_schema_v2.yaml
index c0e315f2..1e6497af 100644
--- a/doc/v2/_static/petab_schema_v2.yaml
+++ b/doc/v2/_static/petab_schema_v2.yaml
@@ -14,6 +14,14 @@ properties:
 
     description: Version of the PEtab format
 
+  id:
+    type: string
+    description: |
+      Identifier of the PEtab problem.
+
+      This is optional and has no effect on the PEtab problem itself.
+    pattern: "^[a-zA-Z_]\\w*$"
+
   parameter_files:
     type: array
     description: |