Example for Checkpoint
For example, use the W3C's RDF to indicate the document's author, the type of content, etc.
The Resource Description Framework (RDF) integrates a variety of web-based metadata activities including sitemaps, content ratings, stream channel definitions, search engine data collection (web crawling), digital library collections, and distributed authoring, using XML as an interchange syntax. Using RDF as a framework, you can integrate different metadata schemes (such as Dublin Core and Government Information Locator Service (GILS), and others) into one package. To learn more about RDF, please visit the W3C RDF home page for an excellent list of resources.
Another example of machine-readable metadata:
Some HTML user agents - recent versions of the LYNX text browser for instance - can build navigation tools from document relations described by the HTML LINK element and "rel" or "rev" attributes (e.g., rel="next", rel="previous", rel="index", etc.), e.g.:
LYNX will build a small menu of links at the top of the page that looks like this:
# prev contents next