expression
it's true to its name; it's just like it says on the box
Used when something lives up to its reputation or advertised quality, often in a positive, slightly colloquial way.
あのラーメン屋は本当に美味しい。看板に偽りなしだ。
That ramen shop is really delicious. It's true to its name.
この掃除機、宣伝通りよく吸う。まさに看板に偽りなし。
This vacuum cleaner really sucks well, just as advertised. It's exactly what it says on the box.
Literally 'no falsehood on the signboard'; a set phrase meaning that something lives up to its advertised claims or reputation.