An exclamation point. "!".
"Period. One." What does that phrase mean to you? Is it two words describing a time? The first class of the day? Or something else? If you guessed anything other than an exclamation point, you'd be dead wrong if you were trying to support one of my users.
While trying to help an end-user login to their machine one morning, I got to the point of point of just manually resetting their password for them.
Our Hero (Me): Your password is now "password123!". Please try and login.
End User: It's still not working!
Our Hero: Hm, that is most definitely your password. Can you please try again?
End User: Ugh. ::saying it out loud as they type:: P-A-S-S-W-O-R-D-ONE-TWO-THREE-PERIOD-ONE.
Our Hero: Wait, what? No, there is an exclamation point at the end.
End User: Yeah, the "period, one".
Our Hero: Period...one...? ::a quick look at my keyboard and I realized what was going on:: Can you type in "password123" and then hit "SHIFT" and the "ONE" key?
End User: Hm, that worked, I'm in. Why didn't you just say that in the first place?
Our Hero: Do you need help with anything else?
End User: No.
Our Hero: Have a nice day. ::click::