For a considerable period of time, statutes have existed which require the registration of deeds, third party incumbrances affecting land, or title to the land itself. In general, the sanction for non-compliance with these registration requirements is that a purchaser for valuable consideration takes free from any interest which should have, but has not, been registered. Throughout the period when registration statutes have been in force, however, a tension has existed between literal compliance with them on the one hand, and seeking to read into them general equitable principles on the other. The effect of introducing these principles is to bind a purchaser by notice of an unregistered interest that is not protected in the appropriate manner by registration.