diff --git a/qr/encoder.go b/qr/encoder.go
index aaa1b60..8c161f9 100644
--- a/qr/encoder.go
+++ b/qr/encoder.go
@@ -11,8 +11,11 @@ type encodeFn func(content string, eccLevel ErrorCorrectionLevel) (*barcode.BitL
 type Encoding byte
 
 const (
+	// Choose best matching encoding
 	Auto Encoding = iota
+	// Encode only numbers [0-9]
 	Numeric
+	// Encode only uppercase letters, numbers and  [Space], $, %, *, +, -, ., /, :
 	AlphaNumeric
 )
 
diff --git a/qr/versioninfo.go b/qr/versioninfo.go
index 7151a25..3653988 100644
--- a/qr/versioninfo.go
+++ b/qr/versioninfo.go
@@ -5,9 +5,13 @@ import "math"
 type ErrorCorrectionLevel byte
 
 const (
+	// Recovers 7% of data
 	L ErrorCorrectionLevel = iota
+	// Recovers 15% of data
 	M
+	// Recovers 25% of data
 	Q
+	// Recovers 30% of data
 	H
 )