diff --git a/mysticeti-core/src/block_handler.rs b/mysticeti-core/src/block_handler.rs
index 52bec399..e3b8355f 100644
--- a/mysticeti-core/src/block_handler.rs
+++ b/mysticeti-core/src/block_handler.rs
@@ -62,6 +62,7 @@ pub struct BenchmarkFastPathBlockHandler {
     consensus_only: bool,
 }
 
+// COMMENT  Here the Block limitations are defined 
 // BenchmarkFastPathBlockHandler can push up to 2x of SOFT_MAX_PROPOSED_PER_BLOCK into block
 // So the value here should be chosen so that 2*SOFT_MAX_PROPOSED_PER_BLOCK*TRANSACTION_SIZE
 // is lower then the maximum allowed block size in the system
@@ -80,6 +81,7 @@ impl BenchmarkFastPathBlockHandler {
         transaction_time: TransactionTimeMap,
     ) -> (Self, mpsc::Sender<Vec<Transaction>>) {
         let (sender, receiver) = mpsc::channel(1024);
+        // COMMENT  Here the transaction log is written
         let transaction_log = TransactionLog::start(config.certified_transactions_log())
             .expect("Failed to open certified transaction log for write");
 
diff --git a/mysticeti-core/src/commit_observer.rs b/mysticeti-core/src/commit_observer.rs
index d9c85c2f..6a2538ba 100644
--- a/mysticeti-core/src/commit_observer.rs
+++ b/mysticeti-core/src/commit_observer.rs
@@ -197,6 +197,7 @@ impl<H: ProcessedTransactionHandler<TransactionLocator> + Send + Sync> CommitObs
     }
 }
 
+//  COMMENT     observe commit events within the consensus system
 pub struct SimpleCommitObserver {
     #[allow(dead_code)] // will be used later during replay
     block_store: BlockStore,
diff --git a/mysticeti-core/src/config.rs b/mysticeti-core/src/config.rs
index 24cc471a..fabd186a 100644
--- a/mysticeti-core/src/config.rs
+++ b/mysticeti-core/src/config.rs
@@ -236,11 +236,14 @@ impl PrivateConfig {
 
 impl Print for PrivateConfig {}
 
+// COMMENT    StorageDir is a wrapper around a path to a directory where the validator stores its data.
 impl StorageDir {
+    // COMMENT    for BenchmarkFastPathBlockHandler
     pub fn certified_transactions_log(&self) -> PathBuf {
         self.path.join("certified.txt")
     }
 
+    // COMMENT    for validator
     pub fn committed_transactions_log(&self) -> PathBuf {
         self.path.join("committed.txt")
     }
diff --git a/mysticeti-core/src/consensus/linearizer.rs b/mysticeti-core/src/consensus/linearizer.rs
index acf0b895..11eedae2 100644
--- a/mysticeti-core/src/consensus/linearizer.rs
+++ b/mysticeti-core/src/consensus/linearizer.rs
@@ -64,6 +64,7 @@ impl CommittedSubDag {
         CommittedSubDag::new(*leader_block_ref, blocks, timestamp_ms, commit_data.height)
     }
 
+    // COMMENT    The current implementation uses key, which is not ideal. We can also let the anchor decide on the order.
     /// Sort the blocks of the sub-dag by round number. Any deterministic algorithm works.
     pub fn sort(&mut self) {
         self.blocks.sort_by_key(|x| x.round());