It's revealed that Norm's real first name is Hilary. Hilary is also the name of George Wendt's child (b. 1985) with his wife Bernadette Birkett (who plays the voice of Norm's wife "Vera" on Cheers).
While Norm's wife Vera is working upstairs at Melville's, she discloses to Rebecca that Norm's real first name is actually Hilary.
It's Frasier's 39th birthday (in Kelsey Grammer it's stated he was born in 1952). Note also that Frasier's birthday is almost in March, which is the month it is mostly in in Frasier.
Carla mentions a Boston restaurant called 'Pizza Pizza Pizza Pizza '. In an episode of Frasier (1993), Dr. Crane reads a radio promo for a Seattle restaurant called 'Pizza Pizza Pizza'.
The "Pizza Pizza Pizza Pizza" name is a reference to Little Caesar's Pizza, which has a two-fer deal that is promoted by the slogan, "Pizza Pizza".