diff --git a/core/src/blockchain/blockchain.rs b/core/src/blockchain/blockchain.rs
index a9a4d99655..cd62679bb8 100644
--- a/core/src/blockchain/blockchain.rs
+++ b/core/src/blockchain/blockchain.rs
@@ -112,7 +112,7 @@ impl BlockChain {
         let header = block.header_view();
         let hash = header.hash();
 
-        ctrace!(BLOCKCHAIN, "Inserting bootstrap block #{}({}) to the blockchain.", header.number(), hash);
+        ctrace!(BLOCKCHAIN, "Inserting floating block #{}({}) to the blockchain.", header.number(), hash);
 
         if self.is_known(&hash) {
             cdebug!(BLOCKCHAIN, "Block #{}({}) is already known.", header.number(), hash);
diff --git a/core/src/client/client.rs b/core/src/client/client.rs
index 54ea12bfd5..df7f3ce4c8 100644
--- a/core/src/client/client.rs
+++ b/core/src/client/client.rs
@@ -152,7 +152,7 @@ impl Client {
 
     /// This is triggered by a message coming from a header queue when the header is ready for insertion
     pub fn import_verified_headers(&self) -> usize {
-        self.importer.import_verified_headers(self)
+        self.importer.import_verified_headers_from_queue(self)
     }
 
     /// This is triggered by a message coming from a block queue when the block is ready for insertion
@@ -445,7 +445,7 @@ impl ImportBlock for Client {
         self.importer.force_update_best_block(hash, self)
     }
 
-    fn import_closed_block(&self, block: &ClosedBlock) -> ImportResult {
+    fn import_generated_block(&self, block: &ClosedBlock) -> ImportResult {
         let h = block.header().hash();
         let update_result = {
             // scope for self.import_lock
@@ -455,7 +455,7 @@ impl ImportBlock for Client {
             let block_data = block.rlp_bytes();
             let header = block.header();
 
-            self.importer.import_headers(vec![header], self, &import_lock);
+            self.importer.import_verified_headers(vec![header], self, &import_lock);
 
             let update_result = self.importer.commit_block(block, header, &block_data, self);
             cinfo!(CLIENT, "Imported closed block #{} ({})", number, h);
diff --git a/core/src/client/importer.rs b/core/src/client/importer.rs
index 29f213f391..72ff5b583b 100644
--- a/core/src/client/importer.rs
+++ b/core/src/client/importer.rs
@@ -94,7 +94,7 @@ impl Importer {
 
             {
                 let headers: Vec<_> = blocks.iter().map(|block| &block.header).collect();
-                self.import_headers(headers, client, &import_lock);
+                self.import_verified_headers(headers, client, &import_lock);
             }
 
             for block in blocks {
@@ -255,14 +255,14 @@ impl Importer {
     }
 
     /// This is triggered by a message coming from a header queue when the header is ready for insertion
-    pub fn import_verified_headers(&self, client: &Client) -> usize {
+    pub fn import_verified_headers_from_queue(&self, client: &Client) -> usize {
         const MAX_HEADERS_TO_IMPORT: usize = 1_000;
         let lock = self.import_lock.lock();
         let headers = self.header_queue.drain(MAX_HEADERS_TO_IMPORT);
-        self.import_headers(&headers, client, &lock)
+        self.import_verified_headers(&headers, client, &lock)
     }
 
-    pub fn import_headers<'a>(
+    pub fn import_verified_headers<'a>(
         &'a self,
         headers: impl IntoIterator<Item = &'a Header>,
         client: &Client,
diff --git a/core/src/client/mod.rs b/core/src/client/mod.rs
index e4ce4e70f0..9a0e674776 100644
--- a/core/src/client/mod.rs
+++ b/core/src/client/mod.rs
@@ -163,17 +163,19 @@ pub trait ImportBlock {
 
     /// Import a trusted header into the blockchain
     /// Trusted header doesn't go through any verifications and doesn't update the best header
+    /// The trusted header may not have parent.
     fn import_trusted_header(&self, header: Header) -> Result<BlockHash, BlockImportError>;
 
     /// Import a trusted block into the blockchain
     /// Trusted block doesn't go through any verifications and doesn't update the best block
+    /// The trusted block may not have parent.
     fn import_trusted_block(&self, block: &Block) -> Result<BlockHash, BlockImportError>;
 
     /// Forcefully update the best block
     fn force_update_best_block(&self, hash: &BlockHash);
 
-    /// Import closed block. Skips all verifications.
-    fn import_closed_block(&self, block: &ClosedBlock) -> ImportResult;
+    /// Import closed block. Skips all verifications. This block is generated by this instance.
+    fn import_generated_block(&self, block: &ClosedBlock) -> ImportResult;
 
     /// Set reseal min timer as reseal_min_period, for creating blocks with transactions which are pending because of reseal_min_period
     fn set_min_timer(&self);
diff --git a/core/src/client/test_client.rs b/core/src/client/test_client.rs
index f4e577d777..805fa4fcd4 100644
--- a/core/src/client/test_client.rs
+++ b/core/src/client/test_client.rs
@@ -474,7 +474,7 @@ impl ImportBlock for TestBlockChainClient {
         unimplemented!()
     }
 
-    fn import_closed_block(&self, _block: &ClosedBlock) -> ImportResult {
+    fn import_generated_block(&self, _block: &ClosedBlock) -> ImportResult {
         Ok(H256::default().into())
     }
 
diff --git a/core/src/miner/miner.rs b/core/src/miner/miner.rs
index 50ca1b8889..5e35f01c06 100644
--- a/core/src/miner/miner.rs
+++ b/core/src/miner/miner.rs
@@ -379,7 +379,7 @@ impl Miner {
             self.engine.proposal_generated(&block);
         }
 
-        chain.import_closed_block(&block).is_ok()
+        chain.import_generated_block(&block).is_ok()
     }
 
     /// Are we allowed to do a non-mandatory reseal?