diff --git a/lib/application.js b/lib/application.js
index 833af91..2631c51 100644
--- a/lib/application.js
+++ b/lib/application.js
@@ -168,6 +168,7 @@ function *respond(next) {
 
   yield *next;
 
+  // allow bypassing koa
   if (false === this.respond) return;
 
   var res = this.res;
@@ -188,21 +189,17 @@ function *respond(next) {
     return res.end();
   }
 
+  // status body
   if (null == body) {
-    // status body
     this.type = 'text';
     body = status[code];
     if (body) this.length = Buffer.byteLength(body);
     return res.end(body);
   }
 
-  // Buffer body
+  // responses
   if (Buffer.isBuffer(body)) return res.end(body);
-
-  // string body
   if ('string' == typeof body) return res.end(body);
-
-  // Stream body
   if (body instanceof Stream) return body.pipe(res);
 
   // body: json