Add rel="nofollow" to URLs in Layered Navigation
SEO URLs module extends default Magento product attribute interface with new tab “SEO URLs”. You can find section “Advanced Properties” there.
Option “Links with ‘nofollow’ in Layered Navigation” adds HTML attribute rel with value “nofollow” to all filter values of current attribute in Layered Navigation.
This optoin works great with Swissup Ajax Layered Navigation as well as with default Magento Layered Navigation.