26 CFR § 301.7601-1
Canvass of districts for taxable persons and objects
June 25, 2020
Each district director shall, to the extent he deems it practicable, cause officers or employees under his supervision and control to proceed, from time to time, through his district and inquire after and concerning all persons therein who may be liable to pay any internal revenue tax, and all persons owning or having the care and management of any objects with respect to which any tax is imposed.
[T.D. 7297, 38 FR 34803, Dec. 19, 1973]