diff --git a/api/share/utils.py b/api/share/utils.py
index 34c9be4609c..2619905ac5e 100644
--- a/api/share/utils.py
+++ b/api/share/utils.py
@@ -70,14 +70,14 @@ def _enqueue_update_share(osfresource):
 
 
 @celery_app.task(bind=True, max_retries=4, acks_late=True)
-def task__update_share(self, guid: str, is_backfill=False):
+def task__update_share(self, guid: str, is_backfill=False, is_supplementary=False):
     """
     This function updates share  takes Preprints, Projects and Registrations.
     :param self:
     :param guid:
     :return:
     """
-    resp = _do_update_share(guid, is_backfill=is_backfill)
+    resp = _do_update_share(guid, is_backfill=is_backfill, is_supplementary=is_supplementary)
     try:
         resp.raise_for_status()
     except Exception as e:
@@ -97,18 +97,22 @@ def task__update_share(self, guid: str, is_backfill=False):
     return resp
 
 
-def pls_send_trove_indexcard(osf_item, *, is_backfill=False):
+def pls_send_trove_indexcard(osf_item, *, is_backfill=False, is_supplementary=False):
     try:
         _iri = osf_item.get_semantic_iri()
     except (AttributeError, ValueError):
         raise ValueError(f'could not get iri for {osf_item}')
-    _metadata_record = pls_gather_metadata_file(osf_item, 'turtle')
+    _metadata_record = pls_gather_metadata_file(osf_item, 'turtle', {
+        'is_supplementary': is_supplementary,
+    })
     _queryparams = {
         'focus_iri': _iri,
-        'record_identifier': _shtrove_record_identifier(osf_item),
+        'record_identifier': _shtrove_record_identifier(osf_item, is_supplementary=is_supplementary),
     }
     if is_backfill:
         _queryparams['nonurgent'] = True
+    if is_supplementary:
+        _queryparams['is_supplementary'] = True
     return requests.post(
         shtrove_ingest_url(),
         params=_queryparams,
@@ -130,7 +134,7 @@ def pls_delete_trove_indexcard(osf_item):
     )
 
 
-def _do_update_share(osfguid: str, *, is_backfill=False):
+def _do_update_share(osfguid: str, *, is_backfill=False, is_supplementary=False):
     logger.debug('%s._do_update_share("%s", is_backfill=%s)', __name__, osfguid, is_backfill)
     _guid_instance = apps.get_model('osf.Guid').load(osfguid)
     if _guid_instance is None:
@@ -139,13 +143,18 @@ def _do_update_share(osfguid: str, *, is_backfill=False):
     _response = (
         pls_delete_trove_indexcard(_resource)
         if _should_delete_indexcard(_resource)
-        else pls_send_trove_indexcard(_resource, is_backfill=is_backfill)
+        else pls_send_trove_indexcard(
+            _resource,
+            is_backfill=is_backfill,
+            is_supplementary=is_supplementary,
+        )
     )
     return _response
 
 
-def _shtrove_record_identifier(osf_item):
-    return osf_item.guids.values_list('_id', flat=True).first()
+def _shtrove_record_identifier(osf_item, *, is_supplementary=False):
+    _id = osf_item.guids.values_list('_id', flat=True).first()
+    return (f'{_id}/supplement' if is_supplementary else _id)
 
 
 def _shtrove_auth_headers(osf_item):
diff --git a/osf/metadata/osf_gathering.py b/osf/metadata/osf_gathering.py
index 9a93f7214fe..9d97782dfff 100644
--- a/osf/metadata/osf_gathering.py
+++ b/osf/metadata/osf_gathering.py
@@ -54,6 +54,13 @@ def osfmap_for_type(rdftype_iri: str):
         raise ValueError(f'invalid OSFMAP type! expected one of {set(OSFMAP.keys())}, got {rdftype_iri}')
 
 
+def osfmap_supplement_for_type(rdftype_iri: str):
+    try:
+        return OSFMAP_SUPPLEMENT[rdftype_iri]
+    except KeyError:
+        return {}
+
+
 ##### END "public" api #####
 
 
@@ -211,6 +218,21 @@ def osfmap_for_type(rdftype_iri: str):
     },
 }
 
+OSFMAP_SUPPLEMENT = {
+    OSF.Project: {
+    },
+    OSF.ProjectComponent: {
+    },
+    OSF.Registration: {
+    },
+    OSF.RegistrationComponent: {
+    },
+    OSF.Preprint: {
+    },
+    OSF.File: {
+    },
+}
+
 OSF_ARTIFACT_PREDICATES = {
     ArtifactTypes.ANALYTIC_CODE: OSF.hasAnalyticCodeResource,
     ArtifactTypes.DATA: OSF.hasDataResource,
diff --git a/osf/metadata/serializers/turtle.py b/osf/metadata/serializers/turtle.py
index 649614b0bfa..4f24b1e2828 100644
--- a/osf/metadata/serializers/turtle.py
+++ b/osf/metadata/serializers/turtle.py
@@ -1,4 +1,4 @@
-from osf.metadata.osf_gathering import osfmap_for_type
+from osf.metadata.osf_gathering import osfmap_for_type, osfmap_supplement_for_type
 from osf.metadata.serializers import _base
 
 
@@ -9,5 +9,8 @@ def filename_for_itemid(self, itemid: str):
         return f'{itemid}-metadata.ttl'
 
     def serialize(self) -> str:
-        self.basket.pls_gather(osfmap_for_type(self.basket.focus.rdftype))
+        if self.serializer_config.get('is_supplementary', False):
+            self.basket.pls_gather(osfmap_supplement_for_type(self.basket.focus.rdftype))
+        else:
+            self.basket.pls_gather(osfmap_for_type(self.basket.focus.rdftype))
         return self.basket.gathered_metadata.serialize(format='turtle')