credence
Say which claim you can't prove
This is the highest-return sentence on any page, and almost nobody writes it.
A site stated plainly that one specific claim — the one a reader would most want confirmed — could not be verified from the site itself. Four different models singled that sentence out, unprompted, across four different questions. It was cited more often than anything the site could prove.
The instinct is that admitting a gap weakens you. The opposite happens: it tells a reader your other claims were filtered. Every site has something it cannot prove. Saying which one is the cheapest credibility available.