You will need to install a user script manager extension to install this script.
This script adds group IDs onto the end of mturk HIT frame urls. This allows you to make userscripts that only activate for specific HITs.
Most HITs are hosted on either mturkcontent.com or s3.amazonaws.com. This can lead to accidents when people have a script running in one HIT that's intended for another. It also leads to a ton of clutter since even inactive scripts are listed on the page in TM/GM.
Now instead of having an include line like this:
// @include https://www.mturkcontent.com*
You can have an include line like this:
// @include https://www.mturkcontent.com*3S1POB7SU8CPQKPT5SXLHVJG57LUQV