Web Viewer 12.1 lets you save various types of internal favorites. Both a specific instance of the report or the latest version of the report can be specified. There are seven different types of internal favorites in Web Viewer.
Internal favorites refers to favorites managed by Web Viewer as opposed to favorites saved using your browser.
How to create Web Viewer favorites?
Release: Web Viewer 12.1
You can save a favorite from the drop down action list next to a report on the report list.
You can also save a favorite from the report list bar.
See the online help.