Merge pull request #29 from pe7er/note-about-double-headers

Added note about double headers #28

README.md

@@ -4,7 +4,7 @@ This Joomla Plugin implements an UI Layer for the HTTP Security headers so every
 
 ## Sponsoring and Donation
 
-You want to support my work for the [development of my extensions](https://extensions.joomla.org/profile/profile/details/200189/) and my work for the [Joomla! Project](https://volunteers.joomla.org/joomlers/248-tobias-zulauf) you can give something back and sponsor me. 
+You want to support my work for the [development of my extensions](https://extensions.joomla.org/profile/profile/details/200189/) and my work for the [Joomla! Project](https://volunteers.joomla.org/joomlers/248-tobias-zulauf) you can give something back and sponsor me.
 
 There are two ways to support me right now:
 - This extension is part of [Github Sponsors](https://github.com/sponsors/zero-24/) by sponsoring me, you help me continue my oss work for the [Joomla! Project](https://volunteers.joomla.org/joomlers/248-tobias-zulauf), write bug fixes, improving features and maintain my extensions.
@@ -31,6 +31,11 @@ This plugin also comes with some easy defaults for:
 - X-Content-Type-Options
 - Referrer-Policy
 
+**Note**: If you have configured some HTTP Security Headers **directly on the server**, then this Plugin might create double entries.
+
+Check the output of your HTTP headers after configuring this HTTP Security Headers Plugin. In Google Chrome: Inspect > Network > the output under Headers).
+In this Plugin you can disable the settings that cause double entries. Also check the Console of your browser for possible errors.
+
 ## Configuration
 
 ### Initial setup the plugin