diff --git a/README.md b/README.md
index 4ee0774..f821cd1 100644
--- a/README.md
+++ b/README.md
@@ -182,6 +182,9 @@ A `FileUploadResult` object is passed to the success callback of the
 
 - Does not support `responseCode` or `bytesSent`.
 
+### Browser Quirks
+
+- __withCredentials__: _boolean_ that tells the browser to set the withCredentials flag on the XMLHttpRequest
 
 ## download
 
@@ -230,6 +233,10 @@ __Parameters__:
 
 - Download requests is being cached by native implementation. To avoid caching, pass `if-Modified-Since` header to download method.
 
+### Browser Quirks
+
+- __withCredentials__: _boolean_ that tells the browser to set the withCredentials flag on the XMLHttpRequest
+
 ## abort
 
 Aborts an in-progress transfer. The onerror callback is passed a FileTransferError object which has an error code of FileTransferError.ABORT_ERR.