Canonical tag - Is it required when you have mobile version of the main site?

[anandsoft]

We have a regular version of a website, say www.mysite.com, optimized for desktop computers, and now, we have developed a mobile version of the same site using a subdomain m.mysite.com. All the urls and pages have been duplicated to a large extent. Our intention is that search engines give full weightage to the desktop pages (main site pages) and the visitors are automatically diverted to the mobile site as necessary using Script on the main site page.

My question is,
1. Do we need to use "alternate" meta tag on the desktop page that points to the corresponding mobile page
2. Do we need to use "canonical" meta tag on the mobile version of the page that points to the corresponding desktop page?

Do we need both the above directives to be used or just "canonical" is sufficient? Are there any other necessary meta tags that need to be addressed?
Appreciate if example code is given for the same.

thanks.

[anandsoft]

I have made some reading for the same and arrived at the following:

"alternate" tag is used on the desktop page (assuming that desktop version of the page is taken as the "canonical", in other words, "original") and "canonical" tag is used on the mobile page. The canonical tag should reference to the desktop equivalent so that the link juice is attributed to the desktop page and there is no duplicate penalty.

Syntax for using "aternate" tag:

<link rel=”alternate” href=”http://m.yourdomain.com/MobilePage.htm” >

Place a rel=alternate tag on each desktop page of your site for which you have a corresponding mobile page. Note that the tag should be placed in the meta tags section of the page.

How do you Implement a Rel=Canonical Link?

Identify the duplicate page (in the sense that the content is duplicate to most part and taken from the original page) on which page you want to implement a rel=canonical, say, MobilePage.htm. Identify the page which will be the target for your rel=canonical, we’ll call that the DesktopPage.htm. Write out the actual canonical tag as follows (shown below).
<link rel=”canonical” href=”http://www.yourdomain.com/DesktopPage.htm” />

Place the tag in the meta tags section of the MobilePage.htm. Update the MobilePage.htm on your live web site.

Basically, canonical tag is put on the duplicate page (Here, MobilePage.htm and points to the origina page using href, here DesktopPage.htm) and "alternate" tag is put on the original page (DesktopPage.htm) and points to the duplicate page (here MobilePage.htm).

In addition to mobile page, you have different landing pages as well that are duplicates of a original content page. There also, you need to use "canonical" tag.

Please correct me if it's not so.

[evejones]

@anandsoft You are correct! Thanks for sharing your knowledge

[anandsoft]

Originally Posted by KevinWillis

@anandsoft Yes, you are correct. Thanks for sharing information.

Thanks for confirmation. We are in the process of updating a couple of our sites to include "alternate" and "canonical" tags.