LC Comment on Primer

Fabien Gandon has spotted this:

Reading he primer I saw what may be a typo: in the following paragraph
you mention twice "three ways of providing description" but you list
only two.
"The final key element of a Description Resource is the actual
description. There are *three *ways of providing this.
     * As RDF (in a "descriptor set")
     * As one or more tags (in a "tag set")
A DR must contain at least one of these *three *and may contain any
greater number of them, none of which may be empty."