It is no longer a secret that the fewer external links a website has in the index of search engines, the better. However, there are cases where you still need to provide a link, for example to clarify something or provide additional information, but you don't want search engine robots to see it. Or you may need to hide analytics counters on the site from being indexed. This raises the natural question: how to block links from indexing? The tags noindex and nofollow can help. The noindex tag was created and introduced by Yandex and should be used when blocking links from that search engine:
<noindex><a href="your‑link‑url">your link text</a></noindex>
The link attribute rel="nofollow" is a Google's creation, used to prevent robots of this search engine from indexing links and looks like this:
<a href="your‑link‑url" rel="nofollow">your link text</a>
Yandex also recognizes the rel="nofollow" attribute as a recommendation to ignore the link.
Considering that most sites receive some (sometimes substantial) organic traffic from both search engines, and therefore the (non)indexation by both Yandex and Google matters, it makes sense to use both of these blocking tags together:
<noindex><a href="your‑link‑url" rel="nofollow">your link text</a></noindex>