The National Information Standards Organization (NISO) has published a new Recommended Practice on Access License and Indicators (NISO RP-22-2015) that defines metadata to be used to indicate free-to-read content and a link to license terms for the use/re-use of that content.
Developed by the NISO Working Group on Access License and Indicators (formerly Open Access Metadata and Indicators), the recommended practice proposes the adoption of two core pieces of metadata and associated tags:
Access and License Indicators (NISO RP-22-2015) is available for free download from the ALI Working Group webpage on the NISO website at: www.niso.org/workrooms/ali.