diff --git a/.gitignore b/.gitignore
index 096a268..5374aed 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,3 +7,4 @@ logs
 .tox
 old
 .*_cache
+.ropeproject
diff --git a/sedr/rodeoprofile10.py b/sedr/rodeoprofile10.py
index ce9f5b3..02dabac 100644
--- a/sedr/rodeoprofile10.py
+++ b/sedr/rodeoprofile10.py
@@ -65,6 +65,42 @@ def requirement7_2(jsondata: str) -> tuple[bool, str]:
     return True, ""
 
 
+def requirement7_3(jsondata) -> tuple[bool, str]:
+    """Check collection identifier. Can only test B, C.
+    This should only be tested if --strict is set."""
+    spec_url = f"{spec_base_url}#_collection_identifier"
+    approved_data_types = [
+        "insitu-observations",
+        "climate_data",
+        "radar_observations",
+        "weather_warnings",
+        "weather_forecast",
+    ]
+
+    # B
+    try:
+        for t in approved_data_types:
+            if jsondata["id"].startswith(t):
+                break
+        else:
+            return (
+                False,
+                f"Collection id SHOULD be from the following list of values: "
+                f"{', '.join(approved_data_types)}. A postfix can be added. "
+                f"Found: <{jsondata['id']}>. See <{spec_url}> for more info.",
+            )
+    except (json.JSONDecodeError, KeyError) as err:
+        return (
+            False,
+            f"Collection must have an id. None found in collection <{jsondata}>."
+            f"Error {err}.",
+        )
+    return (
+        True,
+        "",
+    )
+
+
 def requirement7_4(jsondata: str) -> tuple[bool, str]:
     """Check collection title. Can only test A, B."""
     spec_url = f"{spec_base_url}#_collection_title"
diff --git a/sedr/schemat.py b/sedr/schemat.py
index b65c82f..14c8756 100644
--- a/sedr/schemat.py
+++ b/sedr/schemat.py
@@ -69,7 +69,7 @@ def test_openapi(case):
     except schemathesis.exceptions.CheckFailed as err:
         # raise AssertionError(
         causes = None
-        if err is not None and len(err.causes) > 0:
+        if err is not None and err.causes is not None:
             causes = ", ".join(err.causes[0].args)
         else:
             pass
@@ -156,6 +156,7 @@ def test_edr_conformance(case):
 def test_edr_landingpage(case):
     """Test that the landing page contains required elements."""
     spec_ref = "https://docs.ogc.org/is/19-072/19-072.html#_7c772474-7037-41c9-88ca-5c7e95235389"
+    landingpage_json = None
     response = case.call()
     try:
         landingpage_json = json.loads(response.text)
@@ -167,9 +168,8 @@ def test_edr_landingpage(case):
 
         util.logger.debug("Landingpage %s tested OK", response.url)
     except json.decoder.JSONDecodeError:
-        util.logger.warning(
-            "Landing page is not valid JSON, other formats are not tested yet."
-        )
+        util.logger.warning("Landing page is not valid JSON.")
+        raise AssertionError("Landing page is not valid JSON")
 
     if use_rodeoprofile:
         requirement7_2, requirement7_2_message = rodeoprofile.requirement7_2(
@@ -230,6 +230,12 @@ def test_edr_collections(case):
                 ) from err
 
         if use_rodeoprofile:
+            requirement7_3, requirement7_3_message = rodeoprofile.requirement7_3(
+                jsondata=collection
+            )
+            if not requirement7_3:
+                raise AssertionError(requirement7_3_message)
+
             requirement7_4, requirement7_4_message = rodeoprofile.requirement7_4(
                 jsondata=collection
             )