Preferred Dividends on Diluted EPS formula

I’ve noticed in some examples of DEPS exercises, that they use preferred dividends on the numerator of the DEPS formula, and sometimes they don’t.
Can someone explain when to use it or not just on deps?

You should always subtract preferred dividends when computing basic EPS.

You would not subtract preferred dividends if you have convertible preferred and you’re trying to determine whether or not it’s dilutive; you assume that it’s been converted to common stock.