Beverage can designed to hold a single serving of a beverage

The early metal beverage can was made out of steel, similar to a tin can, and had no pull-tab. Instead, it was opened by a can piercer, a device resembling a bottle opener with a sharp point. The can was opened by punching two triangular holes in the lid — a large one for drinking, and a smaller one to admit air. This type of opener is sometimes referred to as a churchkey. As early as 1936, inventors were applying for patents on self-opening can designs, but the technology of the time made these inventions impractical.
The first all-aluminum cans, like their steel forebears, required use of a can opener. Mikola Kondakow of Thunder Bay, Ontario invented the pull tab version for bottles in 1956 [Canadian patent 476789]. Then, in 1962, Ermal Cleon Fraze of Dayton, Ohio, invented the similar integral rivet and pull-tab version (also known as rimple or ring pull), which had a ring attached at the rivet for pulling, and which would come off completely to be discarded. He received U.S. Patent No. 3,349,949 for his pull-top can design in 1963 and licensed his invention to Alcoa and Pittsburgh Brewing Company, the latter of which first introduced the design on Iron City Beer cans. The first soft drinks to be sold in all-aluminum cans were R.C. Cola and Diet-Rite Cola, both made by the Royal Crown Cola company, in 1964.
The pull-tabs, however, detached easily and were occasionally swallowed accidentally by users. The New England Journal of Medicine reported a case of one person inhaling a pull-tab that had broken off and dropped into the can. The design of the pull-tabs was addressed by Daniel F. Cudzik of Reynolds Metals, who in 1975 developed stay tabs (also called colon tabs). This design would prevent injuries and reduce roadside litter caused by removable tabs, and involves utilizing a scored lid with a pull-tab. The pull-tab can be leveraged to push the scored region into the can, opening up a hole. By the early 1980s, stay tabs had nearly completely replaced pull-tabs in much of the world. However, pull-tabs are still common in places such as China and the Middle East.