diff --git a/README.md b/README.md
index 37ee66b..d5bdebb 100644
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+++ b/README.md
@@ -24,6 +24,12 @@ Usage
 KNACSS is a collection of ready to use styles and snippets to kick start your project. Feel free to use it as a “reset”, then make it grow to suit your needs.
 Take the time to read the documentation before jumping in. Indeed, KNACSS doesn’t always suit beginners’ needs since a little thing can have big consequences.
 
+# Vendor Prefixes 
+
+If you use one of the pre-processed version of KNACSS (LESS / Sass) know that all the properties are declared **without vendor prefixes** (-webkit-,-moz-,-ms-,…), to gain clarity, and length of initial code.
+
+You will certainely need to add these vendor prefixes yourself (this is usually done automatically today with Autoprefixer, Mixture, Prepros, Grunt, etc.).
+
 Useful links
 ------------
 * Website and download : http://knacss.com/