The Australian National Library is adding internet porn to its collection.

The project is aimed at providing material for future social historians, not patrons with bad Google skills.

"The examination of society and culture of a period by necessity involves the study of its sexual life," he wrote in the library's newsletter.

"With this in mind, it is clear that there is no merit in being coy today and therefore delivering an incomplete picture to future researchers."

He cited the usefulness to historians of Victorian pornographic diaries and novels as proof of the importance of collecting contemporary erotica.