diff --git a/schema/bom-1.5.proto b/schema/bom-1.5.proto
index 1f493d141..bea8f9ebe 100644
--- a/schema/bom-1.5.proto
+++ b/schema/bom-1.5.proto
@@ -106,6 +106,7 @@ message Component {
   // Specifies the scope of the component. If scope is not specified, SCOPE_REQUIRED scope should be assumed by the consumer of the BOM
   optional Scope scope = 11;
   repeated Hash hashes = 12;
+  // EITHER (list of SPDX licenses and/or named licenses) OR (tuple of one SPDX License Expression)
   repeated LicenseChoice licenses = 13;
   // An optional copyright notice informing users of the underlying claims to copyright ownership in a published work.
   optional string copyright = 14;
@@ -352,7 +353,7 @@ message License {
   // Licensing details describing the licensor/licensee, license type, renewal and expiration dates, and other important metadata
   optional Licensing licensing = 6;
   // Specifies optional, custom, properties
-  repeated Property properties = 7;  
+  repeated Property properties = 7;
 }
 
 message Licensing {
@@ -431,6 +432,7 @@ message Metadata {
   // The organization that supplied the component that the BOM describes. The supplier may often be the manufacture, but may also be a distributor or repackager.
   optional OrganizationalEntity supplier = 6;
   // The license information for the BOM document
+  // EITHER (list of SPDX licenses and/or named licenses) OR (tuple of one SPDX License Expression)
   optional LicenseChoice licenses = 7;
   // Specifies optional, custom, properties
   repeated Property properties = 8;
@@ -554,6 +556,7 @@ message Service {
   // A boolean value indicating if use of the service crosses a trust zone or boundary. A value of true indicates that by using the service, a trust boundary is crossed. A value of false indicates that by using the service, a trust boundary is not crossed.
   optional bool x_trust_boundary = 9;
   repeated DataFlow data = 10;
+  // EITHER (list of SPDX licenses and/or named licenses) OR (tuple of one SPDX License Expression)
   repeated LicenseChoice licenses = 11;
   // Provides the ability to document external references related to the service.
   repeated ExternalReference external_references = 12;
@@ -650,6 +653,7 @@ message EvidenceCopyright {
 }
 
 message Evidence {
+  // EITHER (list of SPDX licenses and/or named licenses) OR (tuple of one SPDX License Expression)
   repeated LicenseChoice licenses = 1;
   repeated EvidenceCopyright copyright = 2;
   repeated EvidenceIdentity identity = 3;
diff --git a/schema/bom-1.6.proto b/schema/bom-1.6.proto
index 573b44358..26fcc3d00 100644
--- a/schema/bom-1.6.proto
+++ b/schema/bom-1.6.proto
@@ -113,6 +113,7 @@ message Component {
   // Specifies the scope of the component. If a scope is not specified, SCOPE_REQUIRED scope should be assumed by the consumer of the BOM
   optional Scope scope = 11;
   repeated Hash hashes = 12;
+  // EITHER (list of SPDX licenses and/or named licenses) OR (tuple of one SPDX License Expression)
   repeated LicenseChoice licenses = 13;
   // An optional copyright notice informing users of the underlying claims to copyright ownership in a published work.
   optional string copyright = 14;
@@ -483,6 +484,7 @@ message Metadata {
   // The organization that supplied the component that the BOM describes. The supplier may often be the manufacture, but may also be a distributor or repackager.
   optional OrganizationalEntity supplier = 6;
   // The license information for the BOM document. This may be different from the license(s) of the component(s) that the BOM describes.
+  // EITHER (list of SPDX licenses and/or named licenses) OR (tuple of one SPDX License Expression)
   repeated LicenseChoice licenses = 7;
   // Specifies optional, custom, properties
   repeated Property properties = 8;
@@ -612,6 +614,7 @@ message Service {
   // A boolean value indicating if the use of the service crosses a trust zone or boundary. A value of true indicates that by using the service, a trust boundary is crossed. A value of false indicates that by using the service, a trust boundary is not crossed.
   optional bool x_trust_boundary = 9;
   repeated DataFlow data = 10;
+  // EITHER (list of SPDX licenses and/or named licenses) OR (tuple of one SPDX License Expression)
   repeated LicenseChoice licenses = 11;
   // Provides the ability to document external references related to the service.
   repeated ExternalReference external_references = 12;
@@ -711,6 +714,7 @@ message EvidenceCopyright {
 }
 
 message Evidence {
+  // EITHER (list of SPDX licenses and/or named licenses) OR (tuple of one SPDX License Expression)
   repeated LicenseChoice licenses = 1;
   repeated EvidenceCopyright copyright = 2;
   repeated EvidenceIdentity identity = 3;
