diff --git a/README.md b/README.md
index 6848dde..d50db4c 100644
--- a/README.md
+++ b/README.md
@@ -41,6 +41,12 @@ Try changing "network.http.referer.XOriginPolicy" from 2 to 1
 This is related to cookies. Block all of them momentarily changing "network.cookie.cookieBehavior" from 5 to 2
 
 
+`Enabling a string with the value defaultPref("browser.contentblocking.category", "strict/standard/custom"); doesn't work and breaks TCP`
+
+Nevertheless, by using LockPref instead works. Anyway, I prefer not locking this, for example if you want to block all cookies.
+
+
+
 ## Thanks:
 
 * [arkenfox](https://github.com/arkenfox/user.js) - The mayority content of this mozilla.cfg.