What is the relevance of this statement in 7.1.6.1/1 in the C++ Standard?

7.1.6.1/1 contains the following statement (emphasis mine):

There are two cv-qualifiers, const and volatile. If a cv-qualifier appears in a decl-specifier-seq, the init-declarator-list of the declaration shall not be empty.

What is the relevance of the statement in bold above? In other words, is it possible to produce an example of a cv-unqualified type in a decl-specifier-seq, in which the init-declarator-list of the declaration is empty?