IFC (Issued For Construction)
The status of a drawing that has been checked, approved and released for building. It is the only status a contractor should build from — and the only one that carries the issuer’s responsibility for its content.
Anything else — for information, for review, for comment, for tender — is not a construction instruction. Building from it transfers a risk to you that nobody agreed to give you.
And on fast-track projects the pressure to build from pre-IFC drawings is constant and often reasonable, because waiting would stop the job. If you do it, do it with your eyes open: get the instruction in writing, raise the confirmation, and understand that you have accepted the design risk for that element until the IFC drawing arrives and agrees with what you built.