TIL you can use the passwordrules HTML attribute to tell password managers how to generate passwords for you.

Here's an example:

<input type="password" passwordrules="minlength: 20; required: lower; required: upper; required: digit; required: [-];" />

More info on Apple's passwordrules demo site and on Apple's documentation site. There's a WHATWG proposal to standardize this across browsers. It was deadlocked for a long time, with Mozilla being against it, but as of March 2025, Mozilla's position is now positive.

Regardless, there's no harm in using it, and it can only help users who use password managers that support it.