World Taekwondo Federation, commonly known by its acronym WTF, will unofficially change its name to World Taekwondo for marketing and business purposes.
The purpose of the re-branding is to distance the sport from the popular slang term.
WTF is text and social media slang for “What the f**k."
World Taekwondo’s general secretary, Hoss Rafaty, spoke with insidethegames confirming their decision to re-brand.

WTF? World Taekwondo Federation, Why The Face or something else... Source: ABC Australia
"What the f***", so commonplace now that Taekwondo's powers that be felt compelled to distance themselves from it.
The organisation has no plans to change the name officially.
There has also been no comment on changing its logo, which is a stylised version of the acronym.
World Taekwondo has already made changes, renaming the World Taekwondo Grand Prix and World Taekwondo World Championships after a board council discussion in Mexico City earlier this month.

World Taewondo Federation logo. Source: World Taewondo Federation