When the system refuses
Every refusal is a sentence written for the person at the desk, in the manual, findable by pasting it in — and the rule for what gets refused is one line.
"Folio ASARCP-FA000080 has an outstanding balance of 142. Settle it, or bill it to a company or agent first." That is what the system says at the door, and there is a page in the manual with that sentence as its title.
The rule
Refuse only for money. An invoice that has been issued is not edited; a closed month is not posted into; a payment is not deleted; a charge the hotel cannot collect is not posted. Everything else — more people than the room takes, a smaller room, a price below the floor, a block on an occupied room — is a question: say what you see, ask once, write down who said yes.
The sentence
Written in the database, where the rule is enforced, so the same words reach the desk, the booking page and the channel manager. Never a code, never a stack trace, never "an error occurred".
The page
Every refusal has a topic in the manual: what it means, why the system says it, what to do. The public help's search reads the whole body, so pasting the sentence finds the page.