There are several different breed standards for the French Bulldog, from several different countries, or organizations which cover groups of countries.
The FCI, for example, stands for Federation Cynologique Internationale (Basically, International Canine Federation). The FCI standard is what is used in 80 different countries, including Japan, Argentina, Brazil, Greece and Russia.The United Kingdom has its own breed standard, which differs from the FCI standard in several ways.
The CKC standard is from Canada, and differs slightly from the American or AKC breed standard. “CKC” stands for Canadian Kennel Club, and should not be confused with the Continental Kennel Club, a pet registry which was sued by the CKC over the use of their initials for misleading purposes.
The UKC, or United Kennel Club, should not be confused with fly by night registries. Rather, it is an alternative to the AKC which was founded in 1898, and places emphasis on both working abilities, and conformation.
It’s can be interesting to look at the breed standard from several different countries, and see how they differ, and how they are the same. Sometimes it’s as simple as a sentence being worded slightly differently. Here are links to different breed standards for you to have a look at.