diff --git a/cmd/godoc/x.go b/cmd/godoc/x.go
index a3508503ca..0e51ea8172 100644
--- a/cmd/godoc/x.go
+++ b/cmd/godoc/x.go
@@ -22,9 +22,9 @@ type xRepo struct {
 }
 
 var xMap = map[string]xRepo{
-	"codereview": {"https://code.google.com/p/go.codereview", "hg"},
+	"codereview": {"https://code.google.com/p/go.codereview", "hg"}, // Not included at https://golang.org/pkg/#subrepo.
 
-	"arch":       {"https://go.googlesource.com/arch", "git"},
+	"arch":       {"https://go.googlesource.com/arch", "git"}, // Not included at https://golang.org/pkg/#subrepo.
 	"benchmarks": {"https://go.googlesource.com/benchmarks", "git"},
 	"blog":       {"https://go.googlesource.com/blog", "git"},
 	"build":      {"https://go.googlesource.com/build", "git"},
@@ -32,22 +32,22 @@ var xMap = map[string]xRepo{
 	"debug":      {"https://go.googlesource.com/debug", "git"},
 	"exp":        {"https://go.googlesource.com/exp", "git"},
 	"image":      {"https://go.googlesource.com/image", "git"},
-	"lint":       {"https://go.googlesource.com/lint", "git"},
+	"lint":       {"https://go.googlesource.com/lint", "git"}, // Not included at https://golang.org/pkg/#subrepo.
 	"mobile":     {"https://go.googlesource.com/mobile", "git"},
 	"net":        {"https://go.googlesource.com/net", "git"},
-	"oauth2":     {"https://go.googlesource.com/oauth2", "git"},
+	"oauth2":     {"https://go.googlesource.com/oauth2", "git"}, // Not included at https://golang.org/pkg/#subrepo.
 	"perf":       {"https://go.googlesource.com/perf", "git"},
-	"playground": {"https://go.googlesource.com/playground", "git"},
+	"playground": {"https://go.googlesource.com/playground", "git"}, // Not included at https://golang.org/pkg/#subrepo.
 	"review":     {"https://go.googlesource.com/review", "git"},
 	"sync":       {"https://go.googlesource.com/sync", "git"},
 	"sys":        {"https://go.googlesource.com/sys", "git"},
-	"talks":      {"https://go.googlesource.com/talks", "git"},
-	"term":       {"https://go.googlesource.com/term", "git"},
+	"talks":      {"https://go.googlesource.com/talks", "git"}, // Not included at https://golang.org/pkg/#subrepo.
+	"term":       {"https://go.googlesource.com/term", "git"},  // Not included at https://golang.org/pkg/#subrepo.
 	"text":       {"https://go.googlesource.com/text", "git"},
 	"time":       {"https://go.googlesource.com/time", "git"},
 	"tools":      {"https://go.googlesource.com/tools", "git"},
 	"tour":       {"https://go.googlesource.com/tour", "git"},
-	"vgo":        {"https://go.googlesource.com/vgo", "git"},
+	"vgo":        {"https://go.googlesource.com/vgo", "git"}, // Not included at https://golang.org/pkg/#subrepo.
 }
 
 func init() {
diff --git a/godoc/static/package.html b/godoc/static/package.html
index e11b886d01..41b99b4671 100644
--- a/godoc/static/package.html
+++ b/godoc/static/package.html
@@ -317,6 +317,9 @@
 		<li><a href="//godoc.org/golang.org/x/image">image</a> — additional imaging packages.</li>
 		<li><a href="//godoc.org/golang.org/x/mobile">mobile</a> — experimental support for Go on mobile platforms.</li>
 		<li><a href="//godoc.org/golang.org/x/net">net</a> — additional networking packages.</li>
+		<li><a href="//godoc.org/golang.org/x/perf">perf</a> — packages and tools for performance measurement, storage, and analysis.</li>
+		<li><a href="//godoc.org/golang.org/x/review">review</a> — a tool for working with Gerrit code reviews.</li>
+		<li><a href="//godoc.org/golang.org/x/sync">sync</a> — additional concurrency primitives.</li>
 		<li><a href="//godoc.org/golang.org/x/sys">sys</a> — packages for making system calls.</li>
 		<li><a href="//godoc.org/golang.org/x/text">text</a> — packages for working with text.</li>
 		<li><a href="//godoc.org/golang.org/x/time">time</a> — additional time packages.</li>
diff --git a/godoc/static/static.go b/godoc/static/static.go
index df9951307a..b958c3ce8e 100644
--- a/godoc/static/static.go
+++ b/godoc/static/static.go
@@ -1937,6 +1937,9 @@ function cgAddChild(tree, ul, cgn) {
 		<li><a href="//godoc.org/golang.org/x/image">image</a> — additional imaging packages.</li>
 		<li><a href="//godoc.org/golang.org/x/mobile">mobile</a> — experimental support for Go on mobile platforms.</li>
 		<li><a href="//godoc.org/golang.org/x/net">net</a> — additional networking packages.</li>
+		<li><a href="//godoc.org/golang.org/x/perf">perf</a> — packages and tools for performance measurement, storage, and analysis.</li>
+		<li><a href="//godoc.org/golang.org/x/review">review</a> — a tool for working with Gerrit code reviews.</li>
+		<li><a href="//godoc.org/golang.org/x/sync">sync</a> — additional concurrency primitives.</li>
 		<li><a href="//godoc.org/golang.org/x/sys">sys</a> — packages for making system calls.</li>
 		<li><a href="//godoc.org/golang.org/x/text">text</a> — packages for working with text.</li>
 		<li><a href="//godoc.org/golang.org/x/time">time</a> — additional time packages.</li>