diff --git a/source/index.rst b/source/index.rst
index ca0d447..5976b82 100644
--- a/source/index.rst
+++ b/source/index.rst
@@ -81,6 +81,15 @@ documentation:
        (`documentation <https://mammos-project.github.io/mammos>`__)
      - Quantities (values with units).
 
+Magnetic materials domain ontology
+----------------------------------
+
+As part of the MaMMoS project an EMMO-based
+`domain ontology for magnetic materials (MagMO) <https://emmo-repo.github.io/domain-magnetic-materials/>`__
+was created. The development takes place in https://github.com/emmo-repo/domain-magnetic-materials.
+
+The `mammos-entity <https://github.com/mammos-project/mammos-entity>`__ Python package provides a convenient way of annotating raw data with metadata supplied by the ontology (EMMO and MagMO), e.g. by writing metadata-enriched files.
+
 Additional Tools
 ----------------