FAR 19.505
Limitations on Subcontracting and the Nonmanufacturer Rule
What it says
On a small business set-aside for supplies, a dealer/reseller (nonmanufacturer) can qualify only by supplying the end item of a small business manufacturer made in the United States — unless SBA has issued a class waiver for the item.
Why it matters on DIBBS
This is the trap that catches new DIBBS resellers. If you don't make the item, confirm your source is a domestic small manufacturer or that an SBA class waiver exists before you quote a set-aside.