PAM is the PRISM Aggregator Message. PAM is an XML tag set built on the foundation of PRISM metadata and controlled vocabularies. The use case for PAM was originally to encode magazine articles in XML to deliver content to aggregators. While some publishers currently use PAM XML as a content source, that was not the original intent. PAM is an application of PRISM, but PAM and PRISM are not synonymous. PAM is an XML tag set that uses PRISM metadata for a very specific purpose while PRISM remains the core specification for metadata and controlled vocabularies.
The PRISM Specification defines a collection of metadata elements for common publishing needs. But to apply them in specific situations, such as for delivery of content to web sites and secondary licensing partners, it is necessary to define an XML format that combines PRISM metadata with content markup to support those specific processing objectives. The PRISM Aggregator Message is such a specific standard.
The Aggregator XML tag set has been designed to meet the business requirements of the members of the Working Group. After examining numerous samples from every publisher, the group did an extensive review of all requirements and how an aggregator tag set could address them. See the press release for more details. Over time there have been several versions of the PAM schema. The early versions integrated PRISM metadata fields with XHTML tags and was XHTML compliant. With the publication of PAM 3.0 in 2012, the PAM schema integrated PRISM metadata with HTML5.