French Connection has been ordered by the Advertising Standards Authority's Committee of Advertising Practice to pre-vet all its posters for the next two years after the complaint was upheld.
The poster in question stated: "Fcuk FM from Pnuk to Rcok and back. Non-stop Fnuk. Fcuk Fm."
The fashion house now has to get all FCUK-branded posters approved by the CAP copy advice team before poster contractors will accept them for display across UK.
Roger Wisbey, secretary of CAP, said: "French Connection has been warned against using its trademark in a way that many find offensive. The poster pre-vet procedure was introduced for advertisers who have complaints upheld against their posters on the grounds of taste and decency and social responsibility."
In previous rulings, the ASA had warned the advertisers against using its trademark where it could be interpreted in this manner.
In February this year, French Connection came under fire for its poster campaign for its new FCUK Vanity cosmetics range displayed in retailer Boots. The ASA ordered the brand to amend the campaign with help from CAP.
Last year, the ASA ruled another FCUK campaign offensive, when it distributed free condoms with T-shirts bearing the slogan, 'Practice safe sex, go fcuk yourself.'
French Connection launched FCUK in 1997 and since then the ASA has received more than 540 individual compalints about the brand and 150 about FCUK print and poster ads.
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