Relevant Phrases?

I don't see any instruction as to what Relevant phrases are. The description in VbSEO's CP isn't very informative.

Could you please tell me what it is? What it does? And how to use it? I have done a search here but it doesn't appear to be covered yet.

Thanks.

@Kila_Bite:

It is covered in more detail within the announcement:
vBSEO 2.2.0 Released - Google/Yahoo Sitemap Compatible

It adds extra relevant text content to your forum pages. You build up phrases based on information about your forum & then modify your templates to indicate where the content should go.

It is designed in increase your search engine relevancy for the most relevant keywords on each of your pages.