diff --git a/pkg/bitio/README.md b/pkg/bitio/README.md
deleted file mode 100644
index 26d9cd8f..00000000
--- a/pkg/bitio/README.md
+++ /dev/null
@@ -1,18 +0,0 @@
-The bitio package tries to mimic the standard library packages io and bytes as much as possible.
-
-- bitio.Buffer same as bytes.Buffer
-- bitio.IOBitReadSeeker is a bitio.ReaderAtSeeker that from a io.ReadSeeker
-- bitio.IOBitWriter a bitio.BitWriter that write bytes to a io.Writer, use Flush() to write possible unaligned byte
-- bitio.IOReader is a io.Reader that reads bytes from a bit reader, will zero pad on unaligned byte eof
-- bitio.IOReadSeeker is a io.ReadSeeker that read/seek bytes in a bit stream, will zero pad on unaligned - bitio.NewBitReader same as bytes.NewReader
-- bitio.LimitReader same as io.LimitReader
-- bitio.MultiReader same as io.MultiReader
-- bitio.SectionReader same as io.SectionReader
-- bitio.Copy* same as io.Copy*
-- bitio.ReadFull same as io.ReadFull
-
-TODO:
-- bitio.IOBitReader bitio.Reader that reads from a io.Reader
-- bitio.IOBitWriteSeeker bitio.BitWriteSeeker that writes to a io.WriteSeeker
-- bitio.CopyN
-- speed up read by using a cache somehow ([]byte or just a uint64?)
diff --git a/pkg/bitio/doc.go b/pkg/bitio/doc.go
new file mode 100644
index 00000000..9207a8d8
--- /dev/null
+++ b/pkg/bitio/doc.go
@@ -0,0 +1,34 @@
+// Package bitio tries to mimic the standard library packages io and bytes but for bits.
+//
+// - bitio.Buffer same as bytes.Buffer
+//
+// - bitio.IOBitReadSeeker is a bitio.ReaderAtSeeker that reads from a io.ReadSeeker
+//
+// - bitio.IOBitWriter a bitio.BitWriter that writes to a io.Writer, use Flush() to write possible zero padded unaligned byte
+//
+// - bitio.IOReader is a io.Reader that reads bytes from a bitio.Reader, will zero pad unaligned byte at EOF
+//
+// - bitio.IOReadSeeker is a io.ReadSeeker that reads from a bitio.ReadSeeker, will zero pad unaligned byte at EOF
+//
+// - bitio.NewBitReader same as bytes.NewReader
+//
+// - bitio.LimitReader same as io.LimitReader
+//
+// - bitio.MultiReader same as io.MultiReader
+//
+// - bitio.SectionReader same as io.SectionReader
+//
+// - bitio.Copy* same as io.Copy*
+//
+// - bitio.ReadFull same as io.ReadFull
+//
+// TODO:
+//
+// - bitio.IOBitReader bitio.Reader that reads from a io.Reader
+//
+// - bitio.IOBitWriteSeeker bitio.BitWriteSeeker that writes to a io.WriteSeeker
+//
+// - bitio.CopyN
+//
+// - Speed up read by using a cache somehow ([]byte or just a uint64?)
+package bitio
diff --git a/pkg/bitio/iobitreadseeker.go b/pkg/bitio/iobitreadseeker.go
index b2133ec7..48440fe8 100644
--- a/pkg/bitio/iobitreadseeker.go
+++ b/pkg/bitio/iobitreadseeker.go
@@ -5,7 +5,7 @@ import (
 	"io"
 )
 
-// IOBitReadSeeker is a bitio.BitReadAtSeeker reading from a io.ReadSeeker
+// IOBitReadSeeker is a bitio.ReadAtSeeker reading from a io.ReadSeeker
 type IOBitReadSeeker struct {
 	bitPos int64
 	rs     io.ReadSeeker
diff --git a/pkg/bitio/iobitwriter.go b/pkg/bitio/iobitwriter.go
index a7a42160..e51901dd 100644
--- a/pkg/bitio/iobitwriter.go
+++ b/pkg/bitio/iobitwriter.go
@@ -4,7 +4,7 @@ import (
 	"io"
 )
 
-// IOBitWriter is a bitio.BitWriter that writes to a io.Writer
+// IOBitWriter is a bitio.Writer that writes to a io.Writer
 // Use Flush to write possible unaligned byte zero bit padded.
 type IOBitWriter struct {
 	w io.Writer
diff --git a/pkg/bitio/ioreadseeker.go b/pkg/bitio/ioreadseeker.go
index a52be258..3b5a674e 100644
--- a/pkg/bitio/ioreadseeker.go
+++ b/pkg/bitio/ioreadseeker.go
@@ -1,6 +1,6 @@
 package bitio
 
-// IOReadSeeker is a io.ReadSeeker that reads and seeks from a bitio.BitReadSeeker
+// IOReadSeeker is a io.ReadSeeker that reads from a bitio.ReadSeeker
 // Unaligned byte at EOF will be zero bit padded
 type IOReadSeeker struct {
 	IOReader
diff --git a/pkg/bitio/readwrite64.go b/pkg/bitio/readwrite64.go
index 9d3c72b6..b694dc6c 100644
--- a/pkg/bitio/readwrite64.go
+++ b/pkg/bitio/readwrite64.go
@@ -90,6 +90,8 @@ func Read64(buf []byte, firstBit int64, nBits int64) uint64 {
 	return n
 }
 
+// Write64 writes nBits bits large unsigned integer to buf starting from firstBit.
+// Integer is written most significant bit first.
 func Write64(v uint64, nBits int64, buf []byte, firstBit int64) {
 	if nBits < 0 || nBits > 64 {
 		panic(fmt.Sprintf("nBits must be 0-64 (%d)", nBits))