diff --git a/common/hexutil/hexutil.go b/common/hexutil/hexutil.go
index 02c488a3f..46223a281 100644
--- a/common/hexutil/hexutil.go
+++ b/common/hexutil/hexutil.go
@@ -39,6 +39,7 @@ import (
 
 const uintBits = 32 << (uint64(^uint(0)) >> 63)
 
+// Errors
 var (
 	ErrEmptyString   = &decError{"empty hex string"}
 	ErrSyntax        = &decError{"invalid hex string"}
diff --git a/common/math/big.go b/common/math/big.go
index dbf2770a9..9d2e7946d 100644
--- a/common/math/big.go
+++ b/common/math/big.go
@@ -22,12 +22,13 @@ import (
 	"math/big"
 )
 
+// Various big integer limit values.
 var (
 	tt255     = BigPow(2, 255)
 	tt256     = BigPow(2, 256)
 	tt256m1   = new(big.Int).Sub(tt256, big.NewInt(1))
-	MaxBig256 = new(big.Int).Set(tt256m1)
 	tt63      = BigPow(2, 63)
+	MaxBig256 = new(big.Int).Set(tt256m1)
 	MaxBig63  = new(big.Int).Sub(tt63, big.NewInt(1))
 )
 
diff --git a/common/math/integer.go b/common/math/integer.go
index 7eff4d3b0..93b1d036d 100644
--- a/common/math/integer.go
+++ b/common/math/integer.go
@@ -21,8 +21,8 @@ import (
 	"strconv"
 )
 
+// Integer limit values.
 const (
-	// Integer limit values.
 	MaxInt8   = 1<<7 - 1
 	MinInt8   = -1 << 7
 	MaxInt16  = 1<<15 - 1
diff --git a/common/mclock/mclock.go b/common/mclock/mclock.go
index 92005252e..02608d17b 100644
--- a/common/mclock/mclock.go
+++ b/common/mclock/mclock.go
@@ -14,7 +14,7 @@
 // You should have received a copy of the GNU Lesser General Public License
 // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
 
-// package mclock is a wrapper for a monotonic clock source
+// Package mclock is a wrapper for a monotonic clock source
 package mclock
 
 import (
@@ -23,8 +23,10 @@ import (
 	"github.com/aristanetworks/goarista/monotime"
 )
 
-type AbsTime time.Duration // absolute monotonic time
+// AbsTime represents absolute monotonic time.
+type AbsTime time.Duration
 
+// Now returns the current absolute monotonic time.
 func Now() AbsTime {
 	return AbsTime(monotime.Now())
 }
diff --git a/common/number/int.go b/common/number/int.go
index 5b5066970..0cac94254 100644
--- a/common/number/int.go
+++ b/common/number/int.go
@@ -22,9 +22,11 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 )
 
-var tt256 = new(big.Int).Lsh(big.NewInt(1), 256)
-var tt256m1 = new(big.Int).Sub(new(big.Int).Lsh(big.NewInt(1), 256), big.NewInt(1))
-var tt255 = new(big.Int).Lsh(big.NewInt(1), 255)
+var (
+	tt256   = new(big.Int).Lsh(big.NewInt(1), 256)
+	tt256m1 = new(big.Int).Sub(new(big.Int).Lsh(big.NewInt(1), 256), big.NewInt(1))
+	tt255   = new(big.Int).Lsh(big.NewInt(1), 255)
+)
 
 func limitUnsigned256(x *Number) *Number {
 	x.num.And(x.num, tt256m1)
@@ -181,7 +183,6 @@ func (i *Number) FirstBitSet() int {
 }
 
 // Variables
-
 var (
 	Zero       = Uint(0)
 	One        = Uint(1)
diff --git a/common/types.go b/common/types.go
index 12c26d94b..4d374ad24 100644
--- a/common/types.go
+++ b/common/types.go
@@ -29,6 +29,7 @@ import (
 	"github.com/ethereum/go-ethereum/crypto/sha3"
 )
 
+// Lengths of hashes and addresses in bytes.
 const (
 	HashLength    = 32
 	AddressLength = 20