Marginalia, the custom of writing comments in books, is a rich literary pastime. But it has an uncertain fate in a digitalized world.

“People will always find a way to annotate electronically,” said G. Thomas Tanselle, a former vice president of the John Simon Guggenheim Memorial Foundation and an adjunct professor of English at Columbia University in New York. “But there is the question of how it is going to be preserved. And that is a problem now facing collections libraries.”

Wonderful NY Times article on marginalia in the digital age.