Content Management Interoperability Services (CMIS)
"An open standard for controlling content and document management systems and repositories using web protocols. In the early 2000s, there was a boom in content management systems for publishing data online. This included applications like Wordpress, Joomla, Drupal, etc. and many more. This Cambrian explosion of content management systems made it such that if you wanted to move between content providers without losing data all systems needed to follow a specific standard. CMIS was created by The Association for Information Management to help make sure that content published online can be ported freely."
in other words
Zipcodes for the internet.