Pale crag martin to do so, it would cast doubts on their specific distinctness. There are several subspecies differing in plumage shade or size, although the differences are clinal, and races interbreed where their ranges meet. The pale crag martin of the nominate subspecies "P. o. obsoleta" is 12–13 cm (4.7–5.1 in) long with light brown upperparts, becoming paler on the lower back, and a short square tail that has small white patches near the tips of all but the central and outermost pairs of feathers. It has a pale grey throat, upper breast and underwing coverts, and the rest of the underparts
Pale Fire often cited as an important example of metafiction; it has also been called a poioumenon. The connection between "Pale Fire" and hypertext was stated soon after its publication; in 1969, the information-technology researcher Ted Nelson obtained permission from the novel's publishers to use it for a hypertext demonstration at Brown University. A 2009 paper also compares "Pale Fire" to hypertext. The interaction between Kinbote and Shade takes place in the fictitious small college town of New Wye, Appalachia, where they live across a lane from each other, from February to July 1959. Kinbote writes his commentary from then to October