What provides authorization to wear miitary insignia?

[Eclipse]

You'd be wearing the equivalent grade in the respective service, and referring to yourself as the grade designation of the respective service. (i.e, you refer to yourself as SFC in your Army uniform, and MSgt in your CAP uniform)

In either case, you're functioning under authorization of the service, and under their guidelines.
A far cry from violating the law.

The Stolen Valor Act is only applicable to medals and decorations, not grade insignia.

[ßτε]

An E-7 is an E-7 regardless of the branch of service or title for the rank.

A Master Sergeant in the Air Force is an E-7.  A Master Sergeant in the Army is an E-8.  In this case, the title for the rank is NOT equivalent.

They may be wearing an extra rocker they're not entitled to or authorized for. 

Is this Stolen Valor, Title 10, or Title 18?

Dr. Dave

If the individual is a CAP Master Sergeant, the insignia worn on the CAP uniform would be the AF Master Sergeant insignia. The person would not wear Army Master Sergeant insignia on the CAP uniform. The individual would not be "wearing an extra rocker" unless the individual is wearing Army Master Sergeant insignia instead of Sergeant First Class insignia.

[davidsinn]

An E-7 is an E-7 regardless of the branch of service or title for the rank.

A Master Sergeant in the Air Force is an E-7.  A Master Sergeant in the Army is an E-8.  In this case, the title for the rank is NOT equivalent.

They may be wearing an extra rocker they're not entitled to or authorized for. 

Is this Stolen Valor, Title 10, or Title 18?

Dr. Dave

You're missing my point. The rockers don't have any meaning it's the "pay"rate that matters. It's still and E-7.

[BuckeyeDEJ]

If you follow Dr. Dave's logic, an Army master sergeant who re-upped in the Air Force would take a pay cut to keep the same title. It doesn't work that way... the pay grade dictates the rank insignia.

By that same logic, a captain in the Navy (an O-6) would have to take a three-grade cut to be a captain in CAP (an O-3) instead of a lieutenant colonel (the maximum he'd be allowed under regulation).

[DrDave]

Sorry all, I'm not making my question clear.

This has nothing to do with a CAP uniform or rank.

It's E-8 insignia being worn by a retired E-7 on their Army uniform.

Dr. Dave

[Eclipse]

Sorry all, I'm not making my question clear.

This has nothing to do with a CAP uniform or rank.

It's E-8 insignia being worn by a retired E-7 on their Army uniform.

That's not Stolen Valor, might be a Title 10 violation, and probably UCMJ.

Honorary promotion by his local CC on the way out the door, maybe?

[PHall]

Sorry all, I'm not making my question clear.

This has nothing to do with a CAP uniform or rank.

It's E-8 insignia being worn by a retired E-7 on their Army uniform.

Dr. Dave

So he's wearing ARMY Master Sergeant (E-8) grade insignia on his Army uniform? And you know for a fact that he retired as a Sergeant First Class (E-7).

How did you confirm he retired as a E-7?  Military ID card, DD Form 214, Certificate of Retirement from the Armed Forces, Retirement Orders?

I ask this because you're making a fairly serious accusation.

Please confirm the facts before you do anything.

Now if they are wearing the wrong grade insignia on the Army uniform, ask them whats up with that.
The fact that you know they're not wearing the proper grade may well be enough to stop them.

But they will probably leave CAP because of the embarrassment of getting caught.

[PHall]

Honorary promotion by his local CC on the way out the door, maybe?

Nope, not even a possibility. Civilians might get honorary grade, but military members don't, period.

[lordmonar]

TITLE 18 > PART I > CHAPTER 33 > § 702
§ 702. Uniform of armed forces and Public Health Service

Whoever, in any place within the jurisdiction of the United States or in the Canal Zone, without authority, wears the uniform or a distinctive part thereof or anything similar to a distinctive part of the uniform of any of the armed forces of the United States, Public Health Service or any auxiliary of such, shall be fined under this title or imprisoned not more than six months, or both.

No exception for intent under this law. 

Not under the law....but the DA will not go out of his way for someone wearing a halloween costume.