Looks like the good people at the Harvard Law Review who have been aggressively protecting the copyright of our be-loathed Bluebook against all those who would let legal citation free into the wild forgot to renew the copyright on the 10th Edition.

As a consequence, the 10th edition is in the public domain. Public Resource will thus publish an electronic version of the 10th Edition. […]

[W]e have embarked on a joint project with Public Resource to create and publish a public domain version of The Bluebook – a project we refer to as Baby Blue. Our project will mix public domain portions of the 19th edition with newly-created material that implements the Bluebook’s system of citation in a fully usable form.

Couldn’t have happened to a nicer book.