diff --git a/storagegroup/types.proto b/storagegroup/types.proto
index 5f17662..66e23e5 100644
--- a/storagegroup/types.proto
+++ b/storagegroup/types.proto
@@ -7,24 +7,22 @@ option csharp_namespace = "NeoFS.API.v2.StorageGroup";
 
 import "refs/types.proto";
 
-// StorageGroup groups the information about the NeoFS storage group.
-// The storage group consists of objects from single container.
+// StorageGroup keeps verification information for Data Audit sessions. Objects
+// that require payed storage guaranties are gathered in `StorageGroups` with
+// additional information used for proof of storage. `StorageGroup` only
+// contains objects from the same container.
 message StorageGroup {
-  // validation_data_size carries the total size of the payloads of the storage
-  // group members.
+  // Total size of the payloads of objects in the storage group
   uint64 validation_data_size = 1;
 
-  // validation_hash carries homomorphic hash from the concatenation of the
-  // payloads of the storage group members
-  // The order of concatenation is the same as the order of the members in the
-  // Members field.
+  // Homomorphic hash from the concatenation of the payloads of the storage
+  // group members. The order of concatenation is the same as the order of the
+  // members in the `members` field.
   neo.fs.v2.refs.Checksum validation_hash = 2;
 
-  // expiration_epoch carries last NeoFS epoch number of the storage group
-  // lifetime.
+  // Last NeoFS epoch number of the storage group lifetime
   uint64 expiration_epoch = 3;
 
-  // Members carries the list of identifiers of the object storage group members.
-  // The list is strictly ordered.
+  // Strictly ordered list of storage group member objects
   repeated neo.fs.v2.refs.ObjectID members = 4;
 }