If you're wondering what an interest check is, you've come to the right place. An interest check is not mandatory in any way. This is a simple way to provide you with some constructive criticism on your ideas before you formally publish them for others to join.
There are no proper rules for this section. Try and take critisism into consideration at all times, improvement is the key to success.
Any questions or queries, this topic is open so feel free to reply!
-Anorak