# Request SPECification

A Request SPECification (RSPEC) is part of a [Flow Specification](/glossary/f/flowspec), and defines the requirements for a flow.

Different possible service types:

^ Type ^ Description ^ Examples ^
| Best Effort | No guaranteed level of service. | WWW, FTP  |
| Controlled Load | Behaves as Best Effort for an network without load.  |  |
| Guaranteed  | Guarantees a minimum level of service, but no benefit would be provided by higher levels. | Real-time control, latency and delay. |
| Qualitative | Not imediately quantifiable, but better than Best Effort. |  |