diff --git a/api/worker.go b/api/worker.go
index 8d8a966f..642a90ec 100644
--- a/api/worker.go
+++ b/api/worker.go
@@ -1101,7 +1101,7 @@ func (w *Worker) GetMempool(page int, itemsOnPage int) (*MempoolTxids, error) {
 		page = 0
 	}
 	entries := w.mempool.GetAllEntries()
-	pg, from, to, page := computePaging(len(entries), page, itemsOnPage)
+	pg, from, to, _ := computePaging(len(entries), page, itemsOnPage)
 	r := &MempoolTxids{
 		Paging:      pg,
 		MempoolSize: len(entries),
diff --git a/bchain/coins/bellcoin/bellcoinparser.go b/bchain/coins/bellcoin/bellcoinparser.go
index a7e86174..0691c791 100644
--- a/bchain/coins/bellcoin/bellcoinparser.go
+++ b/bchain/coins/bellcoin/bellcoinparser.go
@@ -7,11 +7,13 @@ import (
 	"github.com/martinboehm/btcutil/chaincfg"
 )
 
+// magic numbers
 const (
 	MainnetMagic wire.BitcoinNet = 0xbebacefa
 	TestnetMagic wire.BitcoinNet = 0x0709110b
 )
 
+// chain parameters
 var (
 	MainNetParams chaincfg.Params
 	TestNetParams chaincfg.Params
diff --git a/bchain/coins/dogecoin/dogecoinparser.go b/bchain/coins/dogecoin/dogecoinparser.go
index 109a28ad..1d1d2305 100644
--- a/bchain/coins/dogecoin/dogecoinparser.go
+++ b/bchain/coins/dogecoin/dogecoinparser.go
@@ -10,10 +10,12 @@ import (
 	"github.com/martinboehm/btcutil/chaincfg"
 )
 
+// magic numbers
 const (
 	MainnetMagic wire.BitcoinNet = 0xc0c0c0c0
 )
 
+// chain parameters
 var (
 	MainNetParams chaincfg.Params
 )
diff --git a/bchain/coins/gamecredits/gamecreditsparser.go b/bchain/coins/gamecredits/gamecreditsparser.go
index 225481ac..1507ed77 100644
--- a/bchain/coins/gamecredits/gamecreditsparser.go
+++ b/bchain/coins/gamecredits/gamecreditsparser.go
@@ -7,12 +7,14 @@ import (
 	"github.com/martinboehm/btcutil/chaincfg"
 )
 
+// magic numbers
 const (
 	MainnetMagic wire.BitcoinNet = 0xdbb6c0fb
 	TestnetMagic wire.BitcoinNet = 0x0709110b
 	RegtestMagic wire.BitcoinNet = 0xdab5bffa
 )
 
+// chain parameters
 var (
 	MainNetParams chaincfg.Params
 	TestNetParams chaincfg.Params
diff --git a/bchain/coins/grs/grsparser.go b/bchain/coins/grs/grsparser.go
index 651f922a..a27bc715 100644
--- a/bchain/coins/grs/grsparser.go
+++ b/bchain/coins/grs/grsparser.go
@@ -9,11 +9,13 @@ import (
 	"github.com/martinboehm/btcutil/chaincfg"
 )
 
+// magic numbers
 const (
 	MainnetMagic wire.BitcoinNet = 0xd4b4bef9
 	TestnetMagic wire.BitcoinNet = 0x0709110b
 )
 
+// chain parameters
 var (
 	MainNetParams chaincfg.Params
 	TestNetParams chaincfg.Params
diff --git a/bchain/coins/grs/grsrpc.go b/bchain/coins/grs/grsrpc.go
index 8d4495fa..b31846d3 100644
--- a/bchain/coins/grs/grsrpc.go
+++ b/bchain/coins/grs/grsrpc.go
@@ -9,10 +9,12 @@ import (
 	"github.com/juju/errors"
 )
 
+// GroestlcoinRPC is an interface to JSON-RPC service
 type GroestlcoinRPC struct {
 	*btc.BitcoinRPC
 }
 
+// NewGroestlcoinRPC returns new GroestlcoinRPC instance
 func NewGroestlcoinRPC(config json.RawMessage, pushHandler func(bchain.NotificationType)) (bchain.BlockChain, error) {
 	b, err := btc.NewBitcoinRPC(config, pushHandler)
 	if err != nil {
diff --git a/bchain/coins/litecoin/litecoinparser.go b/bchain/coins/litecoin/litecoinparser.go
index e2557a93..3dc16ba5 100644
--- a/bchain/coins/litecoin/litecoinparser.go
+++ b/bchain/coins/litecoin/litecoinparser.go
@@ -7,12 +7,14 @@ import (
 	"github.com/martinboehm/btcutil/chaincfg"
 )
 
+// magic numbers
 const (
 	MainnetMagic wire.BitcoinNet = 0xdbb6c0fb
 	TestnetMagic wire.BitcoinNet = 0xf1c8d2fd
 	RegtestMagic wire.BitcoinNet = 0xdab5bffa
 )
 
+// chain parameters
 var (
 	MainNetParams chaincfg.Params
 	TestNetParams chaincfg.Params
diff --git a/bchain/coins/nuls/nulsparser.go b/bchain/coins/nuls/nulsparser.go
index 0b6275c1..bf5d8c9b 100644
--- a/bchain/coins/nuls/nulsparser.go
+++ b/bchain/coins/nuls/nulsparser.go
@@ -6,19 +6,22 @@ import (
 	"bytes"
 	"encoding/binary"
 	"encoding/json"
-	"github.com/bsm/go-vlq"
+
+	vlq "github.com/bsm/go-vlq"
 	"github.com/martinboehm/btcutil/base58"
 
 	"github.com/martinboehm/btcd/wire"
 	"github.com/martinboehm/btcutil/chaincfg"
 )
 
+// magic numbers
 const (
 	MainnetMagic wire.BitcoinNet = 0xbd6b0cbf
 	TestnetMagic wire.BitcoinNet = 0xffcae2ce
 	RegtestMagic wire.BitcoinNet = 0xdcb7c1fc
 )
 
+// chain parameters
 var (
 	MainNetParams chaincfg.Params
 	TestNetParams chaincfg.Params
@@ -140,6 +143,7 @@ func (p *NulsParser) UnpackTx(buf []byte) (*bchain.Tx, uint32, error) {
 	return tx, height, nil
 }
 
+// ParseTx parses tx from blob
 func (p *NulsParser) ParseTx(b []byte) (*bchain.Tx, error) {
 	tx := bchain.Tx{}
 	err := json.Unmarshal(b, &tx)
diff --git a/bchain/coins/nuls/nulsrpc.go b/bchain/coins/nuls/nulsrpc.go
index 49e4178f..d800b94d 100644
--- a/bchain/coins/nuls/nulsrpc.go
+++ b/bchain/coins/nuls/nulsrpc.go
@@ -21,7 +21,7 @@ import (
 	"github.com/golang/glog"
 )
 
-// NulsRPC is an interface to JSON-RPC bitcoind service.
+// NulsRPC is an interface to JSON-RPC bitcoind service
 type NulsRPC struct {
 	*btc.BitcoinRPC
 	client   http.Client
@@ -30,7 +30,7 @@ type NulsRPC struct {
 	password string
 }
 
-// NewNulsRPC returns new NulsRPC instance.
+// NewNulsRPC returns new NulsRPC instance
 func NewNulsRPC(config json.RawMessage, pushHandler func(bchain.NotificationType)) (bchain.BlockChain, error) {
 	b, err := btc.NewBitcoinRPC(config, pushHandler)
 	if err != nil {
@@ -101,7 +101,7 @@ type CmdGetVersionInfo struct {
 		MyVersion      string `json:"myVersion"`
 		NewestVersion  string `json:"newestVersion"`
 		NetworkVersion int    `json:"networkVersion"`
-		Infromation    string `json:"infromation"`
+		Information    string `json:"information"`
 	} `json:"data"`
 }
 
@@ -227,7 +227,7 @@ func (n *NulsRPC) GetChainInfo() (*bchain.ChainInfo, error) {
 		Subversion:      versionInfo.Data.NewestVersion,
 		ProtocolVersion: strconv.Itoa(versionInfo.Data.NetworkVersion),
 		Timeoffset:      0,
-		Warnings:        versionInfo.Data.Infromation,
+		Warnings:        versionInfo.Data.Information,
 	}
 	return chainInfo, nil
 }
@@ -414,7 +414,8 @@ func (n *NulsRPC) GetTransaction(txid string) (*bchain.Tx, error) {
 	}
 
 	blockHeaderHeight := getTx.Tx.BlockHeight
-	blockHeader, e := n.GetBlockHeaderByHeight(uint32(blockHeaderHeight))
+	// shouldn't it check the error here?
+	blockHeader, _ := n.GetBlockHeaderByHeight(uint32(blockHeaderHeight))
 	if blockHeader != nil {
 		tx.Blocktime = blockHeader.Time
 	}
diff --git a/bchain/coins/polis/polisparser.go b/bchain/coins/polis/polisparser.go
index 7b56904b..9abf3368 100644
--- a/bchain/coins/polis/polisparser.go
+++ b/bchain/coins/polis/polisparser.go
@@ -2,16 +2,19 @@ package polis
 
 import (
 	"blockbook/bchain/coins/btc"
+
 	"github.com/martinboehm/btcd/wire"
 	"github.com/martinboehm/btcutil/chaincfg"
 )
 
+// magic numbers
 const (
 	MainnetMagic wire.BitcoinNet = 0xbd6b0cbf
 	TestnetMagic wire.BitcoinNet = 0xffcae2ce
 	RegtestMagic wire.BitcoinNet = 0xdcb7c1fc
 )
 
+// chain parameters
 var (
 	MainNetParams chaincfg.Params
 	TestNetParams chaincfg.Params
diff --git a/bchain/coins/polis/polisparser_test.go b/bchain/coins/polis/polisparser_test.go
index b0888dda..6358aa57 100644
--- a/bchain/coins/polis/polisparser_test.go
+++ b/bchain/coins/polis/polisparser_test.go
@@ -3,21 +3,20 @@
 package polis
 
 import (
-	"bytes"
-	"fmt"
 	"blockbook/bchain"
 	"blockbook/bchain/coins/btc"
+	"bytes"
 	"encoding/hex"
+	"fmt"
+	"github.com/martinboehm/btcutil/chaincfg"
 	"io/ioutil"
 	"math/big"
 	"os"
 	"path/filepath"
 	"reflect"
 	"testing"
-	"github.com/martinboehm/btcutil/chaincfg"
 )
 
-
 type testBlock struct {
 	size int
 	time int64
diff --git a/bchain/coins/qtum/qtumparser.go b/bchain/coins/qtum/qtumparser.go
index 29c163f8..477155a9 100644
--- a/bchain/coins/qtum/qtumparser.go
+++ b/bchain/coins/qtum/qtumparser.go
@@ -12,11 +12,13 @@ import (
 	"github.com/martinboehm/btcutil/chaincfg"
 )
 
+// magic numbers
 const (
 	MainnetMagic wire.BitcoinNet = 0xf1cfa6d3
 	TestnetMagic wire.BitcoinNet = 0x0d221506
 )
 
+// chain parameters
 var (
 	MainNetParams chaincfg.Params
 	TestNetParams chaincfg.Params
diff --git a/bchain/coins/vertcoin/vertcoinparser.go b/bchain/coins/vertcoin/vertcoinparser.go
index 1acbc732..deacddc2 100644
--- a/bchain/coins/vertcoin/vertcoinparser.go
+++ b/bchain/coins/vertcoin/vertcoinparser.go
@@ -7,12 +7,14 @@ import (
 	"github.com/martinboehm/btcutil/chaincfg"
 )
 
+// magic numbers
 const (
 	MainnetMagic wire.BitcoinNet = 0xdab5bffb
 	TestnetMagic wire.BitcoinNet = 0x74726576 // "vert" word
 	RegtestMagic wire.BitcoinNet = 0xdab5bffc
 )
 
+// chain parameters
 var (
 	MainNetParams chaincfg.Params
 	TestNetParams chaincfg.Params
diff --git a/tests/dbtestdata/dbtestdata.go b/tests/dbtestdata/dbtestdata.go
index e2f62f05..ab2595a3 100644
--- a/tests/dbtestdata/dbtestdata.go
+++ b/tests/dbtestdata/dbtestdata.go
@@ -8,6 +8,7 @@ import (
 	"github.com/golang/glog"
 )
 
+// Txids, Xpubs and Addresses
 const (
 	TxidB1T1 = "00b2c06055e5e90e9c82bd4181fde310104391a7fa4f289b1704e5d90caa3840"
 	TxidB1T2 = "effd9ef509383d536b1c8af5bf434c8efbf521a4f2befd4022bbd68694b4ac75"
@@ -30,6 +31,7 @@ const (
 	AddrA = "mzVznVsCHkVHX9UN8WPFASWUUHtxnNn4Jj"  // 76a914d03c0d863d189b23b061a95ad32940b65837609f88ac
 )
 
+// Amounts in satoshis
 var (
 	SatZero   = big.NewInt(0)
 	SatB1T1A1 = big.NewInt(100000000)
@@ -45,6 +47,7 @@ var (
 	SatB2T4AA = big.NewInt(1360030331)
 )
 
+// AddressToPubKeyHex is a utility conversion function
 func AddressToPubKeyHex(addr string, parser bchain.BlockChainParser) string {
 	if addr == "" {
 		return ""
@@ -56,6 +59,7 @@ func AddressToPubKeyHex(addr string, parser bchain.BlockChainParser) string {
 	return hex.EncodeToString(b)
 }
 
+// GetTestBitcoinTypeBlock1 returns block #1
 func GetTestBitcoinTypeBlock1(parser bchain.BlockChainParser) *bchain.Block {
 	return &bchain.Block{
 		BlockHeader: bchain.BlockHeader{
@@ -122,6 +126,7 @@ func GetTestBitcoinTypeBlock1(parser bchain.BlockChainParser) *bchain.Block {
 	}
 }
 
+// GetTestBitcoinTypeBlock2 returns block #2
 func GetTestBitcoinTypeBlock2(parser bchain.BlockChainParser) *bchain.Block {
 	return &bchain.Block{
 		BlockHeader: bchain.BlockHeader{
diff --git a/tests/dbtestdata/dbtestdata_ethereumtype.go b/tests/dbtestdata/dbtestdata_ethereumtype.go
index 04ca9956..4208628d 100644
--- a/tests/dbtestdata/dbtestdata_ethereumtype.go
+++ b/tests/dbtestdata/dbtestdata_ethereumtype.go
@@ -5,6 +5,7 @@ import (
 	"encoding/hex"
 )
 
+// Addresses
 const (
 	EthAddr3e         = "3e3a3d69dc66ba10737f531ed088954a9ec89d97"
 	EthAddr55         = "555ee11fbddc0e49a9bab358a8941ad95ffdb48f"
@@ -42,6 +43,7 @@ func unpackTxs(packed []string, parser bchain.BlockChainParser) []bchain.Tx {
 	return r
 }
 
+// GetTestEthereumTypeBlock1 returns block #1
 func GetTestEthereumTypeBlock1(parser bchain.BlockChainParser) *bchain.Block {
 	return &bchain.Block{
 		BlockHeader: bchain.BlockHeader{
@@ -55,6 +57,7 @@ func GetTestEthereumTypeBlock1(parser bchain.BlockChainParser) *bchain.Block {
 	}
 }
 
+// GetTestEthereumTypeBlock2 returns block #2
 func GetTestEthereumTypeBlock2(parser bchain.BlockChainParser) *bchain.Block {
 	return &bchain.Block{
 		BlockHeader: bchain.BlockHeader{
diff --git a/tests/dbtestdata/fakechain.go b/tests/dbtestdata/fakechain.go
index cee7c16b..01545256 100644
--- a/tests/dbtestdata/fakechain.go
+++ b/tests/dbtestdata/fakechain.go
@@ -17,7 +17,7 @@ func NewFakeBlockChain(parser bchain.BlockChainParser) (bchain.BlockChain, error
 	return &fakeBlockChain{&bchain.BaseChain{Parser: parser}}, nil
 }
 
-func (b *fakeBlockChain) CreateMempool(chain bchain.BlockChain) (bchain.Mempool, error) {
+func (c *fakeBlockChain) CreateMempool(chain bchain.BlockChain) (bchain.Mempool, error) {
 	return bchain.NewMempoolBitcoinType(chain, 1, 1), nil
 }
 
@@ -189,6 +189,6 @@ func (c *fakeBlockChain) GetChainParser() bchain.BlockChainParser {
 }
 
 // GetMempoolTransactions returns transactions in mempool
-func (b *fakeBlockChain) GetMempoolTransactions() ([]string, error) {
+func (c *fakeBlockChain) GetMempoolTransactions() ([]string, error) {
 	return nil, errors.New("Not implemented")
 }