VFR Conditions

Weather conditions equal to or better than the minimum for flight under Visual Flight Rules. The term may be used as an ATC clearance/instruction only when:
  1. An IFR aircraft requests a climb/descent in VFR conditions.
  2. The clearance will result in noise abatement benefits where part of the IFR departure route does not conform to an FAA approved noise abatement route or altitude.
  3. A pilot has requested a Practice Instrument Approach and is not on an IFR flight plan.

Note: All pilots receiving this authorization must comply with the VFR visibility and distance from cloud criteria in 14 CFR Part 91. Use of the term does not relieve controllers of their responsibility to separate aircraft in Class B and Class C airspace or TRSAs as required by FAA Order JO 7110.65. When used as an ATC clearance/instruction, the term may be abbreviated "VFR;" e.g., "MAINTAIN VFR," "CLIMB/DESCEND VFR," etc.

Source: Pilot Contoller Glossary (PCG)