Other way (base64):
<link rel="shortcut icon" href="data:image/gif;base64,R0lGODlhEAAQALMAABYAABMmTDZXa2ZkVRxeqzl7zkZvmkJ71m6DLWKPsah+Ko5zV5WUZ8alc/zsKtPU1CH5BAEAAAEALAAAAAAQABAAAARfMMhJq00vv2GlYVrWDBxlGOFzjAhiGkd2EOSALNNJEEVvkK0FLrArHhKGVrBU3B2VAiGzSUgIrjVBAMDter9cRxjgKIsV5jF53RV7zWKzAoB2zNlxMH7sDpfvehJgEQAAOw==">
-data use not cachable (because it is not a file)
-16 colors or less, else huge (must compress)
+no additional http request (because it is not a file)
+the favicon file is never requested (thus no delays)
Or, for off (no data use) (does not request file)
<link rel="icon" href="data:,">
-boring
+fastest
+useful for HFS2.4's login page (especially if web-root has password)
+useful to decrease workload of frequently-hit error page (use only html file instead of html And ico file)