Thanks Eric, lot better said than I put it

It can happen that PA is higher than DA on some sites but from my understanding of this both factors can be important and it depends on the situation. They are both measures of ranking power.

Thanks for clarifying this Rand it is a question that often crops up from savvy clients and you explain it so much better than I could

Firstly I cannot actually think of any legitimate reason for hiding or making a category invisible, however if you had one that means you don’t want the content to be indexed then you would be best blocking that Category within your robots.txt file.

If it is for any other reason and the content is indexable by ANY search engine not just Google then you run the risk of being penalised.

In fact, Google’s guidelines state that, “hiding text or links in your content to manipulate Google’s search rankings can be seen as deceptive and is a violation of Google’s Webmaster Guidelines