Also learned about from Aral’s blog post, the Public Suffix List. Basically, we might submit *.fission.app to make it clear that the * part is “user controlled”, and has impact for how browsers treat various elements.
Heroku is listed:
// Heroku : https://www.heroku.com/
// Submitted by Tom Maher <tmaher AT heroku.com>
herokuapp.com
herokussl.com