diff --git a/2013/bestpractices/bufchan.go b/2013/bestpractices/bufchan.go
index 7f51777..e454b3c 100644
--- a/2013/bestpractices/bufchan.go
+++ b/2013/bestpractices/bufchan.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/bestpractices/bufchanfix.go b/2013/bestpractices/bufchanfix.go
index 560abbd..c183fba 100644
--- a/2013/bestpractices/bufchanfix.go
+++ b/2013/bestpractices/bufchanfix.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/bestpractices/concurrency1.go b/2013/bestpractices/concurrency1.go
index 2b8c333..63a76e1 100644
--- a/2013/bestpractices/concurrency1.go
+++ b/2013/bestpractices/concurrency1.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/bestpractices/concurrency2.go b/2013/bestpractices/concurrency2.go
index 0c4f2f8..c9b1730 100644
--- a/2013/bestpractices/concurrency2.go
+++ b/2013/bestpractices/concurrency2.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/bestpractices/httphandler.go b/2013/bestpractices/httphandler.go
index b9e6c39..bb1b577 100644
--- a/2013/bestpractices/httphandler.go
+++ b/2013/bestpractices/httphandler.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package bestpractices
 
 import (
diff --git a/2013/bestpractices/quitchan.go b/2013/bestpractices/quitchan.go
index 3635b28..7c11cff 100644
--- a/2013/bestpractices/quitchan.go
+++ b/2013/bestpractices/quitchan.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/bestpractices/server.go b/2013/bestpractices/server.go
index b0f2612..e273861 100644
--- a/2013/bestpractices/server.go
+++ b/2013/bestpractices/server.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/bestpractices/shortercode1.go b/2013/bestpractices/shortercode1.go
index ed0e34e..51dffb3 100644
--- a/2013/bestpractices/shortercode1.go
+++ b/2013/bestpractices/shortercode1.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/bestpractices/shortercode2.go b/2013/bestpractices/shortercode2.go
index 3a28e18..082457c 100644
--- a/2013/bestpractices/shortercode2.go
+++ b/2013/bestpractices/shortercode2.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/bestpractices/shortercode3.go b/2013/bestpractices/shortercode3.go
index 0bd896f..47d10a7 100644
--- a/2013/bestpractices/shortercode3.go
+++ b/2013/bestpractices/shortercode3.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/bestpractices/shortercode4.go b/2013/bestpractices/shortercode4.go
index 43aa6bc..fd7f6cc 100644
--- a/2013/bestpractices/shortercode4.go
+++ b/2013/bestpractices/shortercode4.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/bestpractices/shortercode5.go b/2013/bestpractices/shortercode5.go
index e8e67c8..39a280d 100644
--- a/2013/bestpractices/shortercode5.go
+++ b/2013/bestpractices/shortercode5.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/oscon-dl/after.go b/2013/oscon-dl/after.go
index b9ad8e0..021a487 100644
--- a/2013/oscon-dl/after.go
+++ b/2013/oscon-dl/after.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package download
 
 func (s *Server) handleDownload(w http.ResponseWriter, r *http.Request) {
diff --git a/2013/oscon-dl/chunkaligned.go b/2013/oscon-dl/chunkaligned.go
index 644c3fe..d5c0ace 100644
--- a/2013/oscon-dl/chunkaligned.go
+++ b/2013/oscon-dl/chunkaligned.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import "io"
diff --git a/2013/oscon-dl/copy.go b/2013/oscon-dl/copy.go
index cae722a..e778543 100644
--- a/2013/oscon-dl/copy.go
+++ b/2013/oscon-dl/copy.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/oscon-dl/groupcache.go b/2013/oscon-dl/groupcache.go
index 5490e7d..ee18e7c 100644
--- a/2013/oscon-dl/groupcache.go
+++ b/2013/oscon-dl/groupcache.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/oscon-dl/server-compose.go b/2013/oscon-dl/server-compose.go
index 7678912..7865b83 100644
--- a/2013/oscon-dl/server-compose.go
+++ b/2013/oscon-dl/server-compose.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/oscon-dl/server-content.go b/2013/oscon-dl/server-content.go
index b18e792..92aa0ab 100644
--- a/2013/oscon-dl/server-content.go
+++ b/2013/oscon-dl/server-content.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/oscon-dl/server-fs.go b/2013/oscon-dl/server-fs.go
index 7da8851..8a09f55 100644
--- a/2013/oscon-dl/server-fs.go
+++ b/2013/oscon-dl/server-fs.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/oscon-dl/server-hello.go b/2013/oscon-dl/server-hello.go
index c27cc7a..dc846a7 100644
--- a/2013/oscon-dl/server-hello.go
+++ b/2013/oscon-dl/server-hello.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import (
diff --git a/2013/oscon-dl/server.go b/2013/oscon-dl/server.go
index ea33a7a..39655d7 100644
--- a/2013/oscon-dl/server.go
+++ b/2013/oscon-dl/server.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package main
 
 import "net/http"
diff --git a/2013/oscon-dl/sizereaderat.go b/2013/oscon-dl/sizereaderat.go
index 71fd40d..383577c 100644
--- a/2013/oscon-dl/sizereaderat.go
+++ b/2013/oscon-dl/sizereaderat.go
@@ -1,3 +1,5 @@
+// +build ignore,OMIT
+
 package sizereaderat
 
 import (