Schema.org Microdata broadest tag check I have defined the tag that can sit on all the pages of my website and be easily integrated into the admin tool. It is the broadest category with properties that are relevant for all pages.

Can you please tell me if it is written correctly?

I am concerned that the URL code line might be picked up as a circular link and as a result be penalised by the Search Engine:

&lt;div itemscope itemtype="http://schema.org/Thing"&gt;
    &lt;span itemprop="name"&gt;TITLE OF PAGE&lt;/span&gt;
    &lt;span itemprop="description"&gt;CONTENT OF PAGE&lt;/span&gt;
    &lt;link itemprop="url" href="jmb-active.com/?page=URL-OF-THIS-PAGE"&gt;TITLE OF PAGE&lt;/a&gt;
    &lt;img itemprop="image" src="NAME OF IMAGE.jpg" alt="ALT NAME OF IMAGE"/&gt;
&lt;/div&gt;
Schema.org

Assuming that the Thing represents your organization/business on each page of your site, you should try to find a more specific type, e.g., TravelAgency as you point out in the comments.
Every Schema.org type is also implicitly a Thing, so every type can use the basic properties from Thing.

The description property is not for the full content, but only for a "short description" (of the TravelAgency in your case, so it would likely always be the same).

In the same way would the value of the image property have to show an image of the TravelAgency, not just any image.

And the url property would be for the URL of the item, i.e., the TravelAgency, so it would always be the same URL (typically the URL of the home page), no matter on which page.

That said, if you want to have an item that represents each page (and not the business all these pages belong to), you probably want to use WebPage (or one of its sub-types) in addition.

Microdata

Syntactically, your Microdata is fine.

HTML5

Your HTML5 is fine, too, apart from a small error: You have a closing &lt;/a&gt; tag after the link element. You probably want to either use link (i.e., the link is invisible) or a (i.e., the link is visible).