Acrobat XI Deployment Guide for Large Firms - the Adobe Blog
Adobe Reader XI introduced several major upgrades that enhanced user productivity and security:
Users can access a complete set of commenting and markup tools , including sticky notes, highlighter, lines, shapes, and stamps.
Released alongside Windows 8, it included a touch mode to make it easier to use on tablets and touch-screen laptops. System Requirements and Compatibility
I notice you're asking to for Adobe Reader XI — but that version is quite old (released 2012, end-of-life in 2017). You likely mean one of these:
Despite being obsolete, "Adobe Reader XI" remains a common search term. This is usually driven by three factors:
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