diff --git a/README.txt b/README.txt
index 0ba63a04e95583bcc39dcfa0cc22752b0e0d2e44..6dee531f53a70846d4297d59bd0cd5a689dd4308 100644
--- a/README.txt
+++ b/README.txt
@@ -36,4 +36,4 @@ INSTALLATION
 CONFIGURATION
 -------------
 
-When placing a block or section into a layout, this module will add an option for an ID, where only numbers, letters and hyphens are allowed.
+When placing a block or section into a layout, this module will add an option for an ID, where ids follow the protocol of https://developer.mozilla.org/en-US/docs/Web/HTML/Global_attributes/id.