The Danza: Joey Lawrence played Joey in the episode "Big Brother".
Dueling Shows: ABC's Webster [1983-89], starring Emmanuel Lewis as the Gary Coleman equivalent. It even had its own Channel Hop to syndication for its final two years.
Edited for Syndication: The broadcast syndication versions of Diff'rent Strokes (which are also the versions seen on Antenna TV since 2013) feature fairly noticeable (and to some extent, poor) edits for time constraints: the most glaring are the season three episode "The Older Man", in which both a scene dissolve and a wipe take place at almost the same time while transitioning to a scene in which a 25-year-old man who is dating Kimberly ( due to her being mistaken for a 20-year-old, while dressed in makeup and costume for a school play) arrives at the penthouse to take Kimberly out on their date; the episode "The Athlete" from the same season, features a brief clip of a scene in which Willis teaches Kimberly a dance move, which then abruptly switches only two seconds later to the scene in which Willis gets his acceptance letter to Fillmore High ( as promised to him by that school's shady baseball coach, who uses his sister's address to get most of his recruits accepted into the school).
The Other Darrin: Mary Ann Mobley replaced Dixie Carter as Maggie McKinney, the woman who marries Mr. Drummond in the show's seventh season, when Carter left to play Julia Sugarbaker on Designing Women. Similarly, in the two-part "Hooray For Hollywood," which has Arnold and Dudley sneak onto the Knight Rider set, KITT is voiced by someone who is not William Daniels. David Hasselhoffdoes appear, however.
Real-Life Relative: Betty Bridges (Todd Bridges' mother) played the voice of Arnold and Willis' mother on an audio tape in "Memories". She also played the mother of one of Willis' friends in "Willis' Birthday".