| Code | Description | Version |
| ABC | Christian: American Baptist Church | from v2.4 |
| AGN | Agnostic | from v2.4 |
| AME | Christian: African Methodist Episcopal Zion | from v2.4 |
| AMT | Christian: African Methodist Episcopal | from v2.4 |
| ANG | Christian: Anglican | from v2.4 |
| AOG | Christian: Assembly of God | from v2.4 |
| ATH | Atheist | from v2.4 |
| BAH | Baha'i | from v2.4 |
| BAP | Christian: Baptist | from v2.4 |
| BMA | Buddhist: Mahayana | from v2.4 |
| BOT | Buddhist: Other | from v2.4 |
| BRE | Brethren | added v2.6 |
| BTA | Buddhist: Tantrayana | from v2.4 |
| BTH | Buddhist: Theravada | from v2.4 |
| BUD | Buddhist | from v2.4 |
| CAT | Christian: Roman Catholic | from v2.4 |
| CFR | Chinese Folk Religionist | from v2.4 |
| CHR | Christian | from v2.4 |
| CHS | Christian: Christian Science | from v2.4 |
| CMA | Christian: Christian Missionary Alliance | from v2.4 |
| CNF | Confucian | from v2.4 |
| COC | Christian: Church of Christ | from v2.4 |
| COG | Christian: Church of God | from v2.4 |
| COI | Christian: Church of God in Christ | from v2.4 |
| COL | Christian: Congregational | from v2.4 |
| COM | Christian: Community | from v2.4 |
| COP | Christian: Other Pentecostal | from v2.4 |
| COT | Christian: Other | from v2.4 |
| CRR | Christian: Christian Reformed | from v2.4 |
| DOC | Disciples of Christ | added v2.6 |
| EOT | Christian: Eastern Orthodox | from v2.4 |
| EPI | Christian: Episcopalian | from v2.4 |
| ERL | Ethnic Religionist | from v2.4 |
| EVC | Christian: Evangelical Church | from v2.4 |
| FRQ | Christian: Friends | from v2.4 |
| FUL | Christian: Full Gospel | added v2.6 |
| FWB | Christian: Free Will Baptist | from v2.4 |
| GRE | Christian: Greek Orthodox | from v2.4 |
| HIN | Hindu | from v2.4 |
| HOT | Hindu: Other | from v2.4 |
| HSH | Hindu: Shaivites | from v2.4 |
| HVA | Hindu: Vaishnavites | from v2.4 |
| JAI | Jain | from v2.4 |
| JCO | Jewish: Conservative | from v2.4 |
| JEW | Jewish | from v2.4 |
| JOR | Jewish: Orthodox | from v2.4 |
| JOT | Jewish: Other | from v2.4 |
| JRC | Jewish: Reconstructionist | from v2.4 |
| JRF | Jewish: Reform | from v2.4 |
| JRN | Jewish: Renewal | from v2.4 |
| JWN | Christian: Jehovah's Witness | from v2.4 |
| LMS | Christian: Lutheran Missouri Synod | from v2.4 |
| LUT | Christian: Lutheran | from v2.4 |
| MEN | Christian: Mennonite | from v2.4 |
| MET | Christian: Methodist | from v2.4 |
| MOM | Christian: Latter-day Saints | from v2.4 |
| MOS | Muslim | from v2.4 |
| MOT | Muslim: Other | from v2.4 |
| MSH | Muslim: Shiite | from v2.4 |
| MSU | Muslim: Sunni | from v2.4 |
| NAM | Native American | from v2.4 |
| NAZ | Christian: Church of the Nazarene | from v2.4 |
| NOE | Nonreligious | from v2.4 |
| NRL | New Religionist | from v2.4 |
| ORT | Christian: Orthodox | from v2.4 |
| OTH | Other | from v2.4 |
| PEN | Christian: Pentecostal | from v2.4 |
| PRC | Christian: Other Protestant | from v2.4 |
| PRE | Christian: Presbyterian | from v2.4 |
| PRO | Christian: Protestant | from v2.4 |
| QUA | Christian: Friends | from v2.4, removed after v2.5.1 |
| REC | Christian: Reformed Church | from v2.4 |
| REO | Christian: Reorganized Church of Jesus Christ-LDS | from v2.4 |
| SAA | Christian: Salvation Army | from v2.4 |
| SEV | Christian: Seventh Day Adventist | from v2.4 |
| SHN | Shintoist | from v2.4 |
| SIK | Sikh | from v2.4 |
| SOU | Christian: Southern Baptist | from v2.4 |
| SPI | Spiritist | from v2.4 |
| UCC | Christian: United Church of Christ | from v2.4 |
| UMD | Christian: United Methodist | from v2.4 |
| UNI | Christian: Unitarian | from v2.4 |
| UNU | Christian: Unitarian Universalist | from v2.4 |
| VAR | Unknown | from v2.4 |
| WES | Christian: Wesleyan | from v2.4 |
| WMC | Christian: Wesleyan Methodist | from v2.4 |