Re: URLs in your examples?

This is a moot point because the "links" referenced aren't actually links.
For all examples what's provided is a textual representation of the code,
rather than rendered HTML.

Therefore there's no links for a search engine to spider, and so no SEO
benefit to providing any URL (whether valid or invalid) in any examples.

<a href="http://example.com/brand_502/"><span>BRAND 502</span></a> is not a
link:  it's a string of text.  BRAND 502 <http://example.com/brand_502/>
*is* a link, but so such links are to be found in schema.org's examples.