Canonical vs Alternate for country based subdomain dupe content?

[lvdh1]

What's the correct method for tagging dupe content between country based subdomains?

We have:

mydomain.com // default, en-us

www.mydomain.com // en-us

uk.mydomain.com // uk, en-gb

au.mydomain.com // australia, en-au

eu.mydomain.com // europe, en-eu

In the header of each we currently have rel="alternate" tags but we're still getting dupe content warnings in Moz for the "WWW" subdomain.

Question 1) Are we headed in the right direction with using alternate? Or would it be better to use canonical since the languages are technically all English, just different regions. The content is pretty much the same minus currency and localization differences.

Question 2) How can we solve the dupe content between WWW and the base domain, since the above isn't working.

Thanks so much

[gfiorelli1]

Yes.

[lvdh1]

Thanks.

So then I am safe when including all of these on every subdomain?

I have a common header where the above is the exact same for every subdomain (all 4 are always included), which I assume is the correct way?

Also: Why doesn't Moz look at the hreflang tag? I'm very worried about just "ignoring" what the tool says... why is the top SEO tool in the world not capable of correctly detecting dupe content? I'm not sure I'm comfortable with just ignoring the check engine light, so to speak.

[gfiorelli1]

In cases like yours, using the hreflang is the correct way to handle the duplicate content issue, because of the characteristics you yourself cite: currency and localization, which may be tiny differences in terms of "content" but huge in terms of usability and making completely different a product page from another.

Remember that if you canonicalize all the "duplicate" toward the canonical, the canonicalized URLs won't be shown in the countries you're targeting with those URLs... so screwing up the international SEO strategy 100%, so each URL must have as canonical its own URL (self referential), apart the obvious canonicalization rules being applied (e.g.: url with parameter canonicalized to url without parameter).

In case the URL is canonicalized for whatever reason, remember to indicate the canonical URLs in the href of the hreflang annotations. On the contrary Google will start alerting of no-return URLs errors.

Regarding the Moz Pro crawler... don't pay attention to it, because it doesn't consider the hreflang annotation,therefore it will continue saying that those pages are duplicate.