FAR 52.209-1
Qualification Requirements
What it says
Applies when the item requires a qualified product, manufacturer, or process (e.g., a Qualified Products List / QPL or Qualified Manufacturers List / QML). Offers of unqualified sources may be ineligible for award.
Why it matters on DIBBS
If a DIBBS item cites a QPL/QML and you (or your source) are not on it, do not waste the quote — qualification takes months to years. Filter these out early.