Allowed and reserved values
| Value | Meaning | Introduction tag |
|---|---|---|
Y | Decoupled Authentication is supported and is preferred as a primary challenge method if a challenge is necessary (Transaction Status = D in ARes). | Not tagged |
N | Do not use Decoupled Authentication. | Not tagged |
F | Decoupled Authentication is supported and is to be used only as a fallback challenge method if a challenge is necessary (Transaction Status = D in RReq). | Not tagged |
B | Decoupled Authentication is supported and can be used as a primary or fallback challenge method if a challenge is necessary (Transaction Status = D in either ARes or RReq). | Not tagged |
Introduction tags are shown where recorded. An absent tag does not establish when a value was introduced.
Message inclusion
Baseline inclusion. Effective requirements depend on transaction context. Check the field’s conditions and FAQ qualifications; select channel and category in the explorer.
| Message | Baseline inclusion |
|---|---|
| AReq | Optional |
Format and scope
Type: String · Length: 1 character · Minimum length: 1 · Maximum length: 1
- Source components
- 3DS Server
- Device channels
- 01-APP, 02-BRW, 03-3RI
- Message categories
- 01-PA, 02-NPA
Version history
Field introduction tag: 2.2.0. Introduction tags are curated metadata, not a full history of changes. Compare versions and understand coverage.
Source and review status
EMV_3DS_CoreSpec_v2.3.1.1_20230530.pdf, Table A.1, PDF pages 193
Source review status: carried-forward. Carried-forward material has not acquired a new verification claim.
Source document fingerprint
EMV_3DS_CoreSpec_v2.3.1.1_20230530.pdf
6fdf0aba3fc1a765f96b74dad4069d1e189969f38f0023647021687daf589d6bOfficial EMVCo specifications · Methodology and coverage limits