diff --git a/prometheus_client/openmetrics/parser.py b/prometheus_client/openmetrics/parser.py
index 85fdf12c..8edf3a64 100644
--- a/prometheus_client/openmetrics/parser.py
+++ b/prometheus_client/openmetrics/parser.py
@@ -255,6 +255,9 @@ def build_metric(name, documentation, typ, unit, samples):
         # TODO: check info/stateset values are 1/0
         # TODO: check for metadata in middle of samples
         # TODO: Check histogram bucket rules being followed
+        # TODO: Check for duplicate metrics
+        # TODO: Check for dupliate samples
+        # TODO: Check for decresing timestamps
         metric.samples = samples
         return metric