Each episode of the British comedy television series “The Thick of It” (2005-2012) also has a credit for “the cast” under the writer credits. This is due to some of the dialogue being improvised rather than scripted (with the cast credited as providing “additional material”).
Lead actor Peter Capaldi , who played the lead character Malcolm Tucker, said “Fundamentally 80% of the final cut is the script that we started with. The improvisation just makes it feel more real and not written.” Also the series included some very strong language which had an interesting process in being put in. See, prior to rehearsals, the scripts are sent to a “swearing consultant” in Lancaster called Ian Martin, who adds some of the more colourful language.
So, safe to say, the dialogue had a complex touch to it.