If you don't wish to add MediaPass to all the articles of selected categories, you can add it to individual articles manually. Simply wrap the copy you'd like to hide with the MediaPass box with the following tags:

Syntax:

• {mediapass} content {/mediapass}: Use if you wish to show the default media pass settings (based on what you chose on settings)
• {mediapass-overlay} content {/mediapass-overlay} Use if you wish to show the overlay, regardless of what you chose on settings
  
• {mediapass-inpage} content {/mediapass-inpage} Use if you wish to show the in page, regardless of what you chose on settings
  
• {mediapass-video} content {/mediapass-video} Use if you wish to show the video overlay

Video Tutorial: