Update request to Microdata plugin

Google Webmaster indicates that the metadata generated by the Microdata plugin has an error

Error: Page contains property "currency" which is not part of the schema.
It refers to this line <meta itemprop="currency" content="USD"/>

If you look here schema.org/Offer
You will see that the right syntax should be <meta itemprop="priceCurrency" content="USD"/>

I used Nonumber ReReplacer to make the correction "on the fly" in all pages of the site and Google Webmaster confirms the syntax is now correct.

Can you please update the plugin for next version of Hikashop?

Sure, I just added it on our todo list, thanks for your feedback.