Should you use a period after an exclamation point?

It was a query born of laziness.

I was editing a business proposal for a company that has an exclamation point at the end of its name, like Yahoo! but not Yahoo! The company name came up multiple times in the document, sometimes at the end of a sentence.

The writer followed the name with a period: Yahoo!.

Should the period be there?

I was pretty sure I knew the answer: No. And all I had to do was walk a few steps to my bookshelf to check a few style guides. But let’s face it: A few steps are still steps. Plus, turning pages requires physical motion, not to mention the risk of paper-cut.

So, rather than exert all that effort to confirm what I already knew, I stayed in my seat and typed up the question to fellow editors on social media.

The answers I got were surprising and, at the same time, not at all surprising.

For one thing, it’s impossible to ask editors how to handle a passage without some telling you to recast the sentence. “Just reword it so Yahoo! doesn’t appear at the end,” they said. Not helpful. I wanted to know how my colleagues interpreted the punctuation rules in this situation, not how to sidestep the situation.

Others told me to ditch the exclamation point. Again, not what I asked. But that’s partly my fault. My character-count-conscious question neglected to mention that this was a business document written to appeal to executives at the business whose name ends with an exclamation point. The question of whether to tamper with the prospective client’s trademark was above my pay grade. Someone up the chain of command had already decided that messing with their name wouldn’t be the best way to win them over. The exclamation point had to stay.

One commenter noted that the name YAHOO! should be in all capital letters. Again, that’s my fault for not taking the time to explain that Yahoo! wasn’t the actual client. It was just a for-instance.

Eventually, some respondents answered the question exactly as asked, focusing solely on whether a period should immediately follow the exclamation point. Unfortunately, while they did address my question directly, they didn’t give me the answer I wanted. I had come looking for people to confirm what I thought I already knew: No period after Yahoo! “Just tell me I’m right” (a recurring theme for me, by the way).

Most didn’t deliver. Keep the period, they said. The logic of punctuation rules requires it. The exclamation point isn’t ending the sentence. It’s part of the name, so the sentence still needs something to bring it to a close. The consensus was nearly universal.

There were just two dissenters. “I’m leaning toward not doubling up on punctuation,” wrote one editor, who noted that most readers didn’t need a period to understand that the exclamation point didn’t apply to the whole sentence. “In most cases, it should be clear that you are not excited about Yahoo!”

To me, this was all very bad news. It meant I had to get up out of my chair and walk a whole 10 or 12 steps to my bookshelf. But at least there was a payoff for all that physical torment.

The Chicago Manual of Style vindicated me. A period “never accompanies a question mark or an exclamation point. The latter two marks, being stronger, take precedence over the period.” Chicago’s examples don’t include business names with exclamation points, but they do include book and movie titles that end in question marks: She owned two copies of ‘Will You Please Be Quiet, Please?'”

So because there’s no period needed after that question mark, there’s none needed after Yahoo!