Please read Alexey Sklyarenko's annotations on Pale Fire, Ada and other Nabokov works here.
In March, 1905, Demon Veen (in VN's novel Ada, 1969, Van's and Ada's father) perishes in a mysterious airplane disaster above the Pacific. Describing his father's death, Van mentions a maussade Lebanese beauty of fifteen sultry summers:
Describing his dialogues with Ada in "Ardis the First," Van Veen (the narrator and main character in VN’s novel Ada, 1969) mentions ‘minirechi’ (‘talking minarets’) of a secret make that they had evolved in Tartary:
Describing the difference between Terra and Antiterra (Earth’s twin planet also known as Demonia), Van Veen (the narrator and main character in VN’s novel Ada, 1969) mentions the L disaster that happened on Demonia in the beau milieu of the 19th century:
At Kingston (in VN's novel Ada, 1969, Van's American University) there is a first-rate madhouse:
On Demonia (aka Antiterra, Earth's twin planet on which VN's novel Ada, 1969, is set) Ilemna (a subarctic monastery town) was renamed Novostabia:
After Van's first tea party at Ardis Marina (in VN's novel Ada, 1969, Van's, Ada's and Lucette's mother) tells Van that he can see the Tarn from the library window and Ada introduces the view to Van pollice verso:
When Lucette (in VN's novel Ada, 1969, Van's and Ada's half-sister) visits Van at Kingston (Van's American University) bringing him a letter from Ada, Van quips that it is terrible for a window not to be able to turn its paralyzed embrasure and see what is on the other side of the house:
‘I think I’ll take off my jacket,’ she said with the usual flitting frown of feminine fuss that fits the ‘thought.’ ‘You’ve got central heating; we girls have tiny fireplaces.’
In Canto Two of his poem John Shade (the poet in VN’s novel Pale Fire, 1962) describes a TV program that he and his wife Sybil saw on the eve of their daughter's tragic death and mentions Frost (the poet):
I was in time to overhear brief fame
And have a cup of tea with you: my name
Was mentioned twice, as usual just behind
(one oozy footstep) Frost.
In Canto One of his poem John Shade (the poet in VN’s novel Pale Fire, 1962) mentions diamonds of frost:
Retake the falling snow: each drifting flake
Shapeless and slow, unsteady and opaque,
A dull dark white against the day's pale white
And abstract larches in the neutral light.
And then the gradual and dual blue
As night unites the viewer and the view,
And in the morning, diamonds of frost
Describing Kim Beauharnais's album, Van Veen (the narrator and main character in VN’s novel Ada, 1969) uses the phrase "art my foute:"
In an equally casual tone of voice Van said: ‘Darling, you smoke too much, my belly is covered with your ashes. I suppose Bouteillan knows Professor Beauharnais’s exact address in the Athens of Graphic Arts.’