49 C.F.R. §1540.105(a)(2) addresses not only the “sterile area” as related to systems, measures and procedures. It also includes secured areas, AOA’s and SIDA’s. For that reason, the other “systems, measures, or procedures being applied to control access to, or presence or movement in, such areas” are dependent on the particular area at issue. So, for example, in the case of SIDA’s an acceptable system would be the checking of ID’s. On the other hand the definition of sterile area sets forth the specifics for those systems, measures and procedures, which is the screening of persons and property. How is that screening accomplished – through the screening function, which is defined as “inspection of individuals and property for weapons, explosives, and incendiaries.” Until the CFR is amended, that is the TSA's limit for the sterile area.