3DS Authentication Status

`terminalTransStatus`	Meaning	`authenticationStatus` (EMV)	Use case
`AY`	Authentication successful (Frictionless)	`Y`	Success via Frictionless Flow (RBA decision, or successful AAV refresh / recurring for Mastercard)
`CY`	Authentication successful (Challenge)	`Y`	Success via Challenge Flow (RBA decision or 3DS Requestor Challenge Indicator)
`U`	Authentication could not be performed	`U`	ACS-side exception (RReq timeout, SSL/connectivity, invalid RRes, Redis/DB down, HSM error, service-bridge issue)
`A`	Attempts processing performed	`A`	DS could not reach ACS during AReq
`C`	Challenge required	`C`	Challenge (OTP) page in progress, not yet passed/failed. Stays `C` up to 10 min, then flips to `N`
`R`	Issuer rejected	`R`	Issuer rejection (transaction matched a blacklist)
`N`	Not authenticated	`N`	Cardholder clicked "Cancel" on the challenge screen
`CPI`	Challenge load error (pending, initiated)	`N`	Not shown by ACS 2.0
`CPC`	Challenge browser closed (pending, cancelled)	`N`	Challenge page was closed
`CPE`	Challenge external error (pending, expired)	`U`	External error (e.g. service-bridge response error). Contact IT
`CPM`	Challenge ACS malfunction (pending, manual)	`U`	Internal error (e.g. Redis down). Contact IT
`Y`	Authentication successful (not used)	`Y`	Not shown by ACS 2.0
`D`	Decoupled authentication	`D`	Decoupled transaction. Not shown by ACS 2.0
`I`	Informational transaction	`I`	Informational transaction (e.g. `threeDSRequestorChallengeInd=06`)
`IN`	Initial (transition)	(transition)	Transition status, like `C`. Many stuck `C`/`IN` means contact IT