An active clearance is one in which the candidate is presently eligible for access to classified information. A current clearance is one in which a candidate has been determined eligible for access to classified information but is not currently eligible without a reinstatement.
The NCTM Standards evolved over several years, beginning with the 1980 report An Agenda for Action (NCTM, 1980), an important precursor to the NCTM Standards documents. A set of events and circumstances took place in the 1980s that spurred the need for standards and for national direction in mathematics education.
Materials are tested for noncombustibility in ASTM E 136 Standard Test Method for Behavior of Materials in a Vertical Tube Furnace at 750 deg. C. The test exposes small samples of the material to a stream of air heated to 750 deg. C, (1382 deg. F).