Identifies the source of the PartyDetailAltID (1517) value.
| Code | Meaning | 
|---|---|
| 6 | UK National Insurance or Pension Number | 
| 7 | US Social Security Number | 
| 8 | US Employer or Tax ID Number | 
| 9 | Australian Business Number | 
| A | Australian Tax File Number | 
| J | Tax ID | 
| 1 | Korean Investor ID | 
| 2 | Taiwanese Qualified Foreign Investor ID QFII/FID | 
| 3 | Taiwanese Trading Acct | 
| 4 | Malaysian Central Depository (MCD) number | 
| 5 | Chinese Investor ID | 
| I | Directed broker three character acronym as defined in ISITC "ETC Best Practice" guidelines document | 
| B | BIC (Bank Identification Code - SWIFT managed) code (ISO9362 - See "Appendix 6-B") | 
| C | Generally accepted market participant identifier (e.g. NASD mnemonic) | 
| D | Proprietary / Custom code | 
| E | ISO Country Code | 
| F | Settlement Entity Location (note if Local Market Settlement use "E=ISO Country Code") (see "Appendix 6-G" for valid values) | 
| G | Market Identifier Code (ISO 10383) MIC | 
| H | CSD participant/member code (e.g. Euroclear, DTC, CREST or Kassenverein number | 
| K | Australian Company Number | 
| L | Australian Registered Body Number | 
| M | CFTC reporting firm identifier | 
| N | Legal Entity Identifier (ISO 17442) LEI | 
| O | Interim identifier | 
| P | Short code identifier | 
| Q | National ID of natural person | 
| R | India Permanent Account Number | 
| S | Firm designated identifier | 
| T | Special Segregated Account ID | 
| U | Master Special Segregated Account ID |