diff --git a/src/metaschema/oscal_implementation-common_metaschema.xml b/src/metaschema/oscal_implementation-common_metaschema.xml
index f4d5eab2e5..056c6e74b1 100644
--- a/src/metaschema/oscal_implementation-common_metaschema.xml
+++ b/src/metaschema/oscal_implementation-common_metaschema.xml
@@ -304,6 +304,21 @@
+
+
+
+ If a protocol is defined, it should include a start and end port range. To define a single port, the start and end should be the same value.
+
+
+ A start port exists, but an end point does not. To define a single port, the start and end should be the same value.
+
+
+ An end point exists, but a start port does not. To define a single port, the start and end should be the same value.
+
+
+ The port range specified has an end port that is less than the start port.
+
+
To be validated as a natural number (integer >= 1). A single port uses the same value for start and end. Use multiple 'port-range' entries for non-contiguous ranges.