[ColanR]

That would be the copyright date of the book, combined with medical licensing requirements that doctors stay up-to-date in their field.

[astrodust]

Just imagine if software engineers had the same certification requirements as, say, pilots. Or, hell, plumbers.

[ColanR]

I want to say that would be fantastic, except that the software engineers might be pretty miserable.

Also, aren't there such certs already?