No follow in blog posts

There are occasions when a blogger does not want the robots to follow a link, and also when you need to tell Adsense not to serve up ads in line with the content of an individual post. The answer to the 'no follow' used to be to include a meta tag within the HTML code of the post. But I found today that Blogger will no longer accept this. Instead, you need to include rel="nofollow"
within the link code after the URL.
To avoid irrelevant adsense ads, use the following tags:
"!-- google_ad_section_start(weight=ignore) --"
"!-- google_ad_section_end --"
You need to place (< >) at each end of both those tags, they will not print if I place them here.