when stop clicked

Quoted from The Informal and Unofficial List of Rejected Suggestions:
1.2 “When stop sign clicked” hat block
This block would allow users to click the stop sign to run a script. However, the stop sign is designed to stop all the scripts in the project. With this block in place, more scripts will start when you want the project to stop, thus defeating the purpose of the stop sign. Regardless, there are workarounds for this block using the timer or ghost effect blocks; these can be found in this post or this post.
This extends to any block that causes a script to be run as a result of the stop sign being clicked, not just the specific hat block below. For more information, see this post.

when @stopSign clicked :: events :: hat