The British-American Tobacco Company (BAT) was notorious for leaving off their identity on the cards. Many of their sets contain back wording such as "This is one of 50 cards issued with these cigarettes." Since the cigarette brand or manufacturer is not identified, it is not easy to identify these cards. Where it is known that BAT issued these anonymous cards, BAT is identified as the issuer in these checklists, even though there is no mention of BAT on the cards.
There are other anonymous sets listed within these checklists. The identities of the issuing companies is known in some cases, and this is listed where it is known.
There are some sets within this section where I do not know who issued the cards. These are listed at the bottom of these checklists under "Mystery Sets." If you know who issued these sets or any other details about them such as the country where they were issued, please let me know and I will add that information.
There are some anonymous sets that are not listed in this section of the checklists on the Movie Card Website. For example, the Bridgewater, De Beukelaer, Teofani and some other sets are all anonymous sets, but they are not listed here. Though I know this is somewhat confusing, I will try to improve the listings in the future to make it easier to identify all anonymous sets.