"That's right. Commander William Thomas Riker of the USS Enterprise-E." In that moment, Riker felt compelled to say much more, to start rambling on about how the Enterprise was good ship no matter what letter of the alphabet she was on, how George Kirk had every right to be proud of his son, to tell him of what had become of the Federation -- but stopped himself. No, that was out of line, inappropriate.
In much the same way he had to bite his tongue around Zefram Cochrane, Will chose his words more carefully when he spoke next.
"It's an honor to meet you, sir, but if it's all the same to you, please call me Will. No one's in uniform here. No need for us to keep up with rank without it."