Conical tag question

[HateDoingSEO]

I have now 124 notices showing rel = conical as follow ,

can you please advise are they ok , they might be due to new wordpress plugin

URL: http://www.domain.com

Tag value http://www.domain.com

are they ok ?

Although they look same but then why are they there , how can i remove them in word press and is there any reason for them to be left or removed .

My site always uses www, if you put non www address it resolves automatically to www.

My ranking have suddenly dropped as well . can it reason . I am aware of new update .

[NakulGoyal]

Canonical Tags help get rid of any potential duplicate page issues. I don't think this could be a reason for any kind of penalty/drop in rankings.

A canonical tag is simply a code used as a directive by search engine crawlers/spiders to tell search engines what URL is the original version of your webpage.

[Webmaster_SEO]

The above rel canonical on the page is perfectly fine. They should not be reason for your ranking drop and can be left untouched. However, make sure that all pages have canonical set as respective page URLs.

These are generally added give a directive to search engines about the one version of URL to be indexed. Reasons for the same can be numerously like reducing duplicate content on the site (especially ecommercce site) to ensuring the link value passes to main URL where people link to your pages using utm parameters.

You can read more about canonical tags here: http://support.google.com/webmasters/bin/answer.py?hl=en&answer=139394