I'm rewatching 'Dallas' on IMDB TV and just these few are being used in the same ep (at the beginning of S5):
-I'm the "mild sedative" the on-call family doctor gives the wife in emotional distress. I get utilized a lot before the inevitable sanitarium stay.
-I'm the long-lost sibling or half-sibling who swoops into town to create trouble. (Katherine Wentworth, in this case.)
-I'm the custody/divorce battle that is a storyline for high drama, mudslinging, and ongoing tension.
-I'm the one-way phone calls to off-camera characters who are either in contract renegotiations, or they're dead. (Jim Davis, in this case.)