Is there a way to know all the provided shortcuts of a website?

First i'm not sure that this question belongs to this forum. I have hesitated with stackoverflow but this is not really a programming question.(although a program can be a valid answer)

In order to choose what email address to use, i would like to know what shortcuts are proposed by an email provider. That brings me to my question

Is there a way to know all the provided shortcuts of a website?

I don't want to spend time looking for cheatsheet. I don't want a site-specific or site-category specific solution.

solution that I looking for:

1.a addon or 2. a small program that take the website name as paramter or 3. something I haven't think about...