diff --git a/doc.go b/doc.go
index e33528a8..0a6ecd1b 100644
--- a/doc.go
+++ b/doc.go
@@ -84,8 +84,8 @@ message and which bitcoin network the message applies to.  This package provides
 the following constants:
 
 	btcwire.MainNet
-	btcwire.TestNet
-	btcwire.TestNet3
+	btcwire.TestNet  (Regression test network)
+	btcwire.TestNet3 (Test network version 3)
 
 Determining Message Type
 
diff --git a/protocol.go b/protocol.go
index 60935110..b005d371 100644
--- a/protocol.go
+++ b/protocol.go
@@ -83,7 +83,12 @@ type BitcoinNet uint32
 // this package does not provide that functionality since it's generally a
 // better idea to simply disconnect clients that are misbehaving over TCP.
 const (
-	MainNet  BitcoinNet = 0xd9b4bef9
-	TestNet  BitcoinNet = 0xdab5bffa
+	// Main bitcoin network.
+	MainNet BitcoinNet = 0xd9b4bef9
+
+	// Regression test network.
+	TestNet BitcoinNet = 0xdab5bffa
+
+	// Test network version 3.
 	TestNet3 BitcoinNet = 0x0709110b
 )