Salim Khan and Javed Akhtar wrote Zanjeer (1973) together, as Salim-Javed. They wanted a writing credit on the film’s posters. The producer and director, Prakash Mehra, refused. Scroll reports what followed: “the two hired a painter to stencil ‘Written by Salim-Javed’ on posters plastered across Mumbai.”
The credit appeared because the writers put it there themselves.