Linkrot and content drift …

… What the ephemerality of the Web means for your hyperlinks - Columbia Journalism Review. (Hat tip, Dave Lull.)

Hosts control URLs. When they delete a URL’s content, intentionally or not, readers find an unreachable website. This often irreversible decay of Web content is commonly known as linkrot. It is similar to the related problem of content drift, or the typically unannounced changes––retractions, additions, replacement––to the content at a particular URL.