/pr i
    Activates prism inspection tool (your hand holding nothing)
/pr near (radius)
    Shows you actions taken on blocks around you. Default radius is 30 blocks.
/pr page (number)
    Opens the history to the specified page number
        Can use /pr page (next, prev or the page number) to cycle through the pages.
/extinguish (radius)
    Will extinguish any fire within the specified radius.
/pr L (action) r:(radius) since:(time)
    Allows you to search for a specific action being performed in the past within a specified radius of your location.
        Actions can be:
            Break
            Place
            Kill
            Insert
            Remove
            Drop