In the early 1950s, it became popular for supermarkets to offer random weight packaged meats and produce using in-store scales. The Uniform Packaging and Labeling Regulation (UPLR) in NIST Handbook 130, Uniform Laws and Regulations in the Areas of Legal Metrology an Engine Fuel Quality, requires that a random weight label include a Declaration of Identity, Responsibility and Quantity. Due to the technology limitations in the printers of that era, specific exemptions (SI units, type size, location, and free area requirements) were added to the UPLR. The exemptions also apply to standard weight packages labeled using the same equipment, as long as they are labeled in the same manner as random packages. These exemptions are still in place today.
Handbook (NIST HB) - 130
package and labeling, UPLR, Uniform Packaging and Labeling Regulation, Handbook 130, random packages