The Posting Library is a feature that can be found on the Publish tab and consists of a library where you can save and share posts templates.
The main functionalities are:
Saving posts as templates
The Save as Template option is now available inside the post form. It works for new and already existing posts (it can help if you are willing to duplicate posts too).
Templates will be displayed in a "library"
Saved templates are displayed on top of the Publish tab, in a section called Template library.
Sharing templates with other users
Templates can be shared by the template owner. Sharing makes a template visible to other users that have at least one business in common with them.
Creating, selecting, editing and deleting a template from the library
Templates can also be created from the library. In order to use an existing template, you can hover the mouse on it and click View. The posting page will open and it can be applied to any post type.
Template owners and Admins can edit and delete them. This won't remove or edit past publications created using this template.