These two page types look similar on the surface, but they have different trust contracts. If they blur together, the site stops being reliable.
Official authority lists stay official-first. Directory pages are clearly labeled as non-official and only exist when there is real public inventory to show.
An approved tester page can point to an official utility list or city-maintained lookup. It can also show clearly separated sponsor inventory, but only below the authority block and without implying endorsement.
A non-official directory can help users discover local testers, but it cannot borrow the language or visual hierarchy of an authority list. If there is no real public inventory, the page should not render.
The common failure mode is taking a city page that mentions tester registration and presenting it as though the site itself maintains the approved roster. That is exactly the ambiguity this project avoids.
Official tester lists and commercial directories must stay separate. Authority pages lead with the governing source; non-official directories are explicitly labeled and only go live when real inventory exists.
What counts as an official source, how local utility pages override generic assumptions, and why stale pages are suppressed.
What a failed backflow test usually means, how repair and retest sequencing works, and where owners lose time.
How to think about annual testing, repair, and retest pricing without confusing a market quote with the compliance rule.
A practical guide to the property types, hazard classes, and devices that usually trigger backflow assembly requirements.