Initially, you can use this for ability scores during character creation.
Use the code 8m4d6v1r1 then drop your highest and lowest roll
During the game you can use this thread if you'd like to make some rolls (combat, saves, skills, etc...) seperately from the game thread so that you can work the results into your IC post.
It can also be used to make extra die rolls at the end of your turn to account for rolls that might be made later in the round (AoOs, saves, counters, etc...). In this case, you may want to label each roll. If not, the rolls will be used in chronological order, as needed.
Of course these in-game uses are entirely optional, as you can simply add them to you in-character post in a spoiler box instead.