diff --git a/Documentation/ProjectFile/prj/parameters/parameter/Group/c_Group.md b/Documentation/ProjectFile/prj/parameters/parameter/Group/c_Group.md
new file mode 100644
index 0000000000000000000000000000000000000000..08feb54ca7a0fa9a2945cab34aecc271e2228ff0
--- /dev/null
+++ b/Documentation/ProjectFile/prj/parameters/parameter/Group/c_Group.md
@@ -0,0 +1,5 @@
+Group parameter (also known as a material dependent parameter) defines a
+specific value or values for each of the group ids.
+
+The group_id_property specifies the field in the mesh (MeshLib::Properties) from
+which the group ids are used.
diff --git a/Documentation/ProjectFile/prj/parameters/parameter/Group/t_group_id_property.md b/Documentation/ProjectFile/prj/parameters/parameter/Group/t_group_id_property.md
new file mode 100644
index 0000000000000000000000000000000000000000..576add64edccf5d980a0ff86143dc43a7109a788
--- /dev/null
+++ b/Documentation/ProjectFile/prj/parameters/parameter/Group/t_group_id_property.md
@@ -0,0 +1 @@
+\ogs_missing_documentation