Chapter 28. Catalog data in search engines

Table of Contents

Details of the mapping
Viewing microdata
Other helpful features for search engines

Each record in the catalog is displayed to search engines using microdata.


Make sure your system administrator has not added a restrictive robots.txt file to your server. These files restrict search engines, up to the point of not allowing search engines to index your site at all.

Details of the mapping

  • Each item is listed as a schema:Offer, which is the same category that an online bookseller might use to describe an item for sale. These Offers are always listed with a price of $0.00.
  • Subject headings are exposed as schema:about properties.
  • Electronic resources are assigned a schema:url property, and any notes or link text are assigned a schema:description property.
  • Given a Library of Congress relator code for 1xx and 7xx fields, Evergreen surfaces the URL for that relator code along with the schema:contributor property to give machines a better chance of understanding how the person or organization actually contributed to this work.
  • Linking out to related records:

    • Given an LCCN (010 field), Evergreen links to the corresponding Library of Congress record using schema:sameAs.
    • Given an OCLC number (035 field, subfield a beginning with (OCoLC)), Evergreen links to the corresponding WorldCat record using schema:sameAs.
    • Given a URI (024 field, subfield 2 = 'uri'), Evergreen links to the corresponding OCLC Work Entity record using schema:exampleOfWork.