One of the biggest problems with the current implementation of the Internet is that information is not adequately dated for the purposes of search and understanding the relevance of information being viewed. For instance, an education page that discusses the Pythagorean theorem has no expiration date; the information is good foerver. However, a page that describes prices must have an effective date and an expiration date.

PDFs should have effective date and expiration date fields in metadata. Moreover, when a user opens a PDF and the current system time is outside the effective date to expiration date range that the author has specified in Properties, the user should get an alert.

Because many casual users are unfamiliar with Properties, and many PDFs are created through the print interface of a word-processing program, the interface for entering these two dates should be part of the Create/Save PDF process.

The default effective date should be the current system date. The defa