It is very often claimed that the scripts for Mork and Mindy would explicitly mark places where Robin Williams was to improvise, using language such as "Mork does his thing" or "Robin does something ...
At the end of every episode of Mork & Mindy, the alien visitor Mork calls his boss Orson to give a report. The show depicts the call by having Mork chant, "Mork calling Orson. Come in, Orson!" ...
Happy Days maintained a fairly realistic bent throughout it's run (I'm not here to debate shark jumping, I promise). Two notable detours from this were Mork and Mindy and Out of the Blue. Mork ...