Beer dating codes
Since beer in cans was new, breweries also opted to display the type of beer in very prominent (sometimes more prominent than the brand of beer) letters.
Early cans tend to have "Ale," "Beer," "Bock," or "Lager" in very large letters.
In other words, if you want to send e-mail to a beer company, don't send it to me.
"Budweiser", "Bud Dry" "Bud Light", "Busch", "Michelob", "Michelob Light", and "O'Doul's" are registered trademarks of Anheuser-Busch, Inc.
The largest brewery in the United States, Anheuser-Busch jump-started the dating controversy (mostly an effort to make smaller breweries look bad) by changing their date codes in 1996.
They used no less than different coding schemes that year, resulting in fairly widespread confusion.
Early flat tops often displayed a "Cool Before Serving" line on the front of the can or "Keglined" on the front of the can.
For an explanation of the types of beer cans below, see "Types of Beer Cans." Publications can be helpful in establishing the date of cans: "American Breweries II" by Dale Van Wieren: this book is a listing of all known American Breweries, their formal titles, addresses and dates of operation.
With many exceptions, steel cans generally date between 19 and aluminum cans date after 1980.
US Patent and Trademark Office: online, searcable database.