The French Connection is a company founded in the United Kingdom in 1969 which sells clothing and accessories in many parts of the world. In April 1997, French Connection began branding their clothes "fcuk" (usually written in lowercase). Though they insisted it was an acronym for French Connection United Kingdom, its similarity to the word "fuck" caused controversy.
French Connection fully exploited this and produced an extremely popular range of t-shirts with messages such as "fcuk this", "mile high fcuk", "lucky fcuk", "fcuk on the beach", etc. There were also a number of regionally specific messages, such as "no fcukin worries" (in Australia) and "fcuk off". Designer Daniel Greenwood later sued the company for inconsistency in shirt titles and lack of lenience.
Apparently they first discovered the acronym when a fax was sent from their Hong Kong store FCHK to FCUK.
In 2001, during the introduction of French Connection in San Francisco, big banners hung on the front of the newly opened store saying "San Francisco's first fcuk."