diff --git a/pallets/groupsign/src/lib.rs b/pallets/groupsign/src/lib.rs
index 1de5485c..fddc88d2 100644
--- a/pallets/groupsign/src/lib.rs
+++ b/pallets/groupsign/src/lib.rs
@@ -196,6 +196,7 @@ pub mod pallet {
                     ));
                     post_info.actual_weight
                 }
+                // SPB review: shouldn't the error be returned (w/ groupsign call weight added) ?
                 Err(err) => err.post_info.actual_weight,
             };
 
diff --git a/runtime/src/lib.rs b/runtime/src/lib.rs
index 15724998..435842c8 100644
--- a/runtime/src/lib.rs
+++ b/runtime/src/lib.rs
@@ -515,6 +515,9 @@ impl pallet_author_mapping::Config for Runtime {
 // Filter slots between collators (in nutshell author slot filter pallet chooses who's producer for each slot).
 impl pallet_author_slot_filter::Config for Runtime {
     type Event = Event;
+    // SBP review: pallet-randomness-collective-flip does not provide a safe source of randomness.
+    // PParachains will have a reliable source of randomness from the relay chain consensus (see https://github.com/paritytech/cumulus/issues/463).
+    // 
     type RandomnessSource = RandomnessCollectiveFlip;
     type PotentialAuthors = ParachainStaking;
 }
@@ -1020,7 +1023,7 @@ construct_runtime!(
         NodeBlock = generic::Block<Header, sp_runtime::OpaqueExtrinsic>,
         UncheckedExtrinsic = UncheckedExtrinsic
     {
-
+        // SBP review: specify an enum value for all variant
         System: frame_system::{Pallet, Call, Config, Storage, Event<T>},
         RandomnessCollectiveFlip: pallet_randomness_collective_flip::{Pallet, Storage},
         Timestamp: pallet_timestamp::{Pallet, Call, Storage, Inherent},