diff --git a/src/components/net/fetch/cors_cache.rs b/src/components/net/fetch/cors_cache.rs
index 529edc683f7..fb6676e8064 100644
--- a/src/components/net/fetch/cors_cache.rs
+++ b/src/components/net/fetch/cors_cache.rs
@@ -2,6 +2,13 @@
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+//! An implementation of the [CORS preflight cache](http://fetch.spec.whatwg.org/#cors-preflight-cache)
+//! For now this library is XHR-specific.
+//! For stuff involving `
`, `