tracker/udp/client.go      | 2 ++
 tracker/udp/conn-client.go | 8 ++++++--
 tracker/udp/dispatcher.go  | 1 +

diff --git a/tracker/udp/client.go b/tracker/udp/client.go
index aea3ec91fe69f5c552f4ba5259a30dc77778918a..8b072e62fef4b8db7b3027814ce7da4cb8a98293 100644
--- a/tracker/udp/client.go
+++ b/tracker/udp/client.go
@@ -11,6 +11,8 @@ 	"sync"
 	"time"
 )
 
+// Client interacts with UDP trackers via its Writer and Dispatcher. It has no knowledge of
+// connection specifics.
 type Client struct {
 	mu           sync.Mutex
 	connId       ConnectionId
diff --git a/tracker/udp/conn-client.go b/tracker/udp/conn-client.go
index ac920ed099d8aa4df2e4cd9edc6644b8dadb40c6..81e139c96151fbd856d95b5bd528a9456193e1db 100644
--- a/tracker/udp/conn-client.go
+++ b/tracker/udp/conn-client.go
@@ -9,11 +9,15 @@ 	"github.com/anacrolix/missinggo/v2"
 )
 
 type NewConnClientOpts struct {
+	// The network to operate to use, such as "udp4", "udp", "udp6".
 	Network string
-	Host    string
-	Ipv6    *bool
+	// Tracker address
+	Host string
+	// If non-nil, forces either IPv4 or IPv6 in the UDP tracker wire protocol.
+	Ipv6 *bool
 }
 
+// Manages a Client with a specific connection.
 type ConnClient struct {
 	Client  Client
 	conn    net.Conn
diff --git a/tracker/udp/dispatcher.go b/tracker/udp/dispatcher.go
index 3aad927e3848bfb5cbe742cd1c294ea4b6e9790a..7fc3e1b346e68c88d9523ff89294242ac758a4b2 100644
--- a/tracker/udp/dispatcher.go
+++ b/tracker/udp/dispatcher.go
@@ -6,6 +6,7 @@ 	"fmt"
 	"sync"
 )
 
+// Maintains a mapping of transaction IDs to handlers.
 type Dispatcher struct {
 	mu           sync.RWMutex
 	transactions map[TransactionId]Transaction