I had a question recently that set my old brain to churning. A simple enough question: “Is the rule of underlining words to denote italics no longer fashionable?”
Hmm, very interesting.
In my opinion—and I daresay the opinions of most editors—the underlining of italicized words was only necessary back in the typewriter days when there was no way to italicize words. Now that we all use word processors, we can use actual italics and it looks great.
As long as (ah, here comes the exception), the font being used allows a clear difference between the regular and italicized words. For example, if you’re using something like Courier font, there’s not a lot of difference between them. But, fonts like Times New Roman have a good, clear difference.
So, yes, I would say use actual italics and forget the underlining rule. By the way, the underlining rule for book, movie, etc titles is still in effect, but many editors (and again I'm guessing) prefer the italicized versions. To me, anything underlined in a manuscript is to be viewed as emphasized, as in someone shouting. But, then again (I really should stop this), I prefer to see the shouting italicized rather than underlined.