| PSC | Description
|
| B502 | Special Studies/analysis- Air Quality |
| B503 | Special Studies/analysis- Archeological/paleontological |
| B504 | Special Studies/analysis- Chemical/biological |
| B505 | Special Studies/analysis- Cost Benefit |
| B506 | Special Studies/analysis- Data (other Than Scientific) |
| B507 | Special Studies/analysis- Economic |
| B509 | Special Studies/analysis- Endangered Species: Plant/animal |
| B510 | Special Studies/analysis- Environmental Assessments |
| B513 | Special Studies/analysis- Feasibility (non-construction) |
| B516 | Special Studies/analysis- Animal/fisheries |
| B517 | Special Studies/analysis- Geological |
| B518 | Special Studies/analysis- Geophysical |
| B519 | Special Studies/analysis- Geotechnical |
| B520 | Special Studies/analysis- Grazing/range |
| B521 | Special Studies/analysis- Historical |
| B522 | Special Studies/analysis- Legal |
| B524 | Special Studies/analysis- Mathematical/statistical |
| B525 | Special Studies/analysis- Natural Resource |
| B526 | Special Studies/analysis- Oceanological |
| B527 | Special Studies/analysis- Recreation |
| B528 | Special Studies/analysis- Regulatory |
| B529 | Special Studies/analysis- Scientific Data |
| B530 | Special Studies/analysis- Seismological |
| B532 | Special Studies/analysis- Soil |
| B533 | Special Studies/analysis- Water Quality |
| B534 | Special Studies/analysis- Wildlife |
| B537 | Special Studies/analysis- Medical/health |
| B538 | Special Studies/analysis- Intelligence |
| B539 | Special Studies/analysis- Aeronautical/space |
| B540 | Special Studies/analysis- Building Technology |
| B541 | Special Studies/analysis- Defense |
| B542 | Special Studies/analysis- Educational |
| B543 | Special Studies/analysis- Energy |
| B544 | Special Studies/analysis- Technology |
| B545 | Special Studies/analysis- Housing/community Development |
| B546 | Special Studies/analysis- Security (physical/personal) |
| B547 | Special Studies/analysis- Accounting/financial Management |
| B548 | Special Studies/analysis- Trade Issue |
| B549 | Special Studies/analysis- Foreign/national Security Policy |
| B550 | Special Studies/analysis- Organization/administrative/personnel |
| B551 | Special Studies/analysis- Mobilization/preparedness |
| B552 | Special Studies/analysis- Manpower |
| B553 | Special Studies/analysis- Communications |
| B554 | Special Studies/analysis- Acquisition Policy/procedures |
| B555 | Special Studies/analysis- Elderly/handicapped |
| B599 | Special Studies/analysis- Other |