diff --git a/httprl.module b/httprl.module
index d85e049..c0e979a 100644
--- a/httprl.module
+++ b/httprl.module
@@ -132,6 +132,15 @@ function httprl_build_url_self($path = '', $detect_schema = FALSE) {
  * @param array $options
  *   (optional) An array that can have one or more of the following elements:
  *   - headers: An array containing request headers to send as name/value pairs.
+ *     Some of the more useful headers:
+ *     - For POST: 'Content-Type' => 'application/x-www-form-urlencoded',
+ *     - Limit number of bytes server sends back: 'Range' => 'bytes=0-1024',
+ *     - Let server know where request came from: 'Referer' => 'example.com',
+ *     - Content-Types that are acceptable: 'Accept' => 'text/plain',
+ *     - Send Cookies: 'Cookie' => 'key1=value1; key2=value2;',
+ *     - Skip the cache: 'Cache-Control' => 'no-cache',
+ *     - Skip the cache: 'Pragma' => 'no-cache',
+ *     List of headers: http://en.wikipedia.org/wiki/List_of_HTTP_header_fields
  *   - method: A string containing the request method. Defaults to 'GET'.
  *   - data: A string containing the request body, formatted as
  *     'param=value&param=value&...'. Defaults to NULL.