Additional indexing attributes.
Additional indexing attributes.

oreillymedia/HTMLBook,mushroomgithub/HTMLBook,oreillymedia/HTMLBook,wastemobile/HTMLBook,oreillymedia/HTMLBook,gitenberg-dev/HTMLBook,gitenberg-dev/HTMLBook,gitenberg-dev/HTMLBook,mushroomgithub/HTMLBook,macmillanpublishers/HTMLBook,macmillanpublishers/HTMLBook,macmillanpublishers/HTMLBook,wastemobile/HTMLBook,mushroomgithub/HTMLBook