The "Weezy F. Baby, and the F is for phenomenal" line off Lil Wayne's 2009 track "Yes" is among his most iconic.
According to Wayne's manager Cortez Bryant, the F was a big mistake and one that infuriated Wayne. [Jump to 19 minutes.]
"The word starts with 'ph,' but he said 'f,' right?” Bryant says during an interview with Fake Shore Drive. “He was like, ‘Oh sh-t, I gotta change that.’ But We released it. But I'm like bro ... We had an argument about that. He not understanding the concept about digital, and it’s gone non. We had pressed tons of CDs, but he didn’t realize he spelled it wrong, and I didn’t catch it. Wayne is a perfectionist about that words, using his words and prepositions in [the] correct way,” Bryant continued. “He might misspell something on purpose for lyrical exercise and wordplay, but, you know, he’s really precise about his wordplay. He was really down, pissed, ‘F-ck the whole mixtape’ just because of that one damn line and that's his biggest goddamn song."
So there you go.