> RFC 4122 defines a Uniform Resource Name (URN) namespace for UUIDs. A UUID presented as a URN appears as follows:[1]

> > urn:uuid:123e4567-e89b-12d3-a456-426655440000

https://en.wikipedia.org/wiki/Universally_unique_identifier#...

Version 4 UUIDs have 122 random bits (out of 128 bits total).

In Python:

  >>> import uuid
  >>> _id = uuid.uuid4()
  >>> _id.urn
  'urn:uuid:4c466878-a81b-4f22-a112-c704655fa4ee'

Whether search engines will consider a URL or a URN or a random str without dashes to be one searchable-for token is pretty ironic in terms of extracting relations between resources in a Linked Data hypergraph.

  >>> _id.hex
  '4c466878a81b4f22a112c704655fa4ee'

The relation between a resource and a Thing with a URI/URN/URL can be expressed with https://schema.org/about . In JSON-LD ("JSONLD"):

  {"@context": "https://schema.org",
   "@type": "WebPage",
   "about": {
     "@type": "SoftwareApplication",
     "identifier": "urn:uuid:4c466878-a81b-4f22-a112-c704655fa4ee",
     "url": ["", ""],
     "name": [
       "a schema.org/SoftwareApplication < CreativeWork < Thing",
       {"@value": "a rose by any other name",
        "@language": "en"}]}}

Or with RDFa:

  <body vocab="https://schema.org/" typeof="WebPage">
    <div property="about" typeof="SoftwareApplication">
      <meta property="identifier" content="urn:uuid:4c466878-a81b-4f22-a112-c704655fa4ee"/>
      <a property="url" href=""></a>
      <a property="url" href=""></a>
      <span property="name">a schema.org/SoftwareApplication &lt; CreativeWork &lt; Thing</span>
      <span property="name" lang="en">a rose by any other name</span>
    </div>
  </body>

Or with Microdata:

  <div itemtype="https://schema.org/WebPage" itemscope>
    <link itemprop="http://www.w3.org/ns/rdfa#usesVocabulary" href="https://schema.org/" />
    <div itemprop="about" itemtype="https://schema.org/SoftwareApplication" itemscope>
      <a itemprop="url" href=""></a>
      <a itemprop="url" href=""></a>
      <meta itemprop="identifier" content="urn:uuid:4c466878-a81b-4f22-a112-c704655fa4ee" />
      <meta itemprop="name" content="a schema.org/SoftwareApplication &lt; CreativeWork &lt; Thing"/>
      <meta itemprop="name" content="a rose by any other name" lang="en"/>
    </div>
  </div>