Justifying active tense and second person singular

["Halter, Meg" <HalterMC -at- navair -dot- navy -dot- mil>]

Hi Folks --

I'm writing a user guide for a piece of software and my boss feels strongly
that the active tense and second person singular is "too personal". For
example, he changed 

"If none of the models meet your requirements, you can add a new model in
one of three ways."

to

"If none of the models meet the user's requirements, a new model can be
added in one of three ways."

Now I can find ample references to support my position that this is a Bad
Thing. My question is this: Does anyone out there have a US Government
standard or style guide that specifically states that the active tense and
first and second person pronouns are good? (I checked with the style guide
here locally, and it doesn't address the subject.)

Thanks for your help.

-- Meg