When Willow tells Dawn about her attraction to women, she uses the exact same words she did in the season three's Doppelgangland (1999) to describe her evil vampire self: "And I think I'm kinda gay!".
The tweed suit worn by Spike in his guise as Giles' son "Randy Giles" is the same one used in Restless (2000) for Xander's dream, where he also described Giles as "Like a father to me".
The title "tabula rasa", Latin for "blank slate", is a reference to the theory that individuals are born without built-in mental content and that therefore all knowledge comes from experience or perception.
The neighborhood Buffy and Spike fight in is the Desperate Housewives (2004) neighborhood set (also used in the film The 'Burbs (1989)).
The episode does not translate well into other languages. A sizable part of the humor is the interplay between Giles and Spike, laced with British idiom and Americans' stereotyped views of England; the puns based on "Randy" are meaningless in other languages. In French, "Randy" is translated to "Candide", possibly a reference to the Voltaire novel. Buffy's assumed name "Joan" is left as "Joan" in French, and the reference to Joan of Arc ("Jeanne d'Arc" in French) is mostly lost. Dawn's reference to Xander as "Alex", a more common shortened form of "Alexander", lacks significance in the French translation because he has been named Alex in France since "Welcome to the Hellmouth".