Commit be6efd9

A name is said to have \defn{linkage} when it can denote the same

object, reference, function, type, template, namespace or value as a

name introduced by a declaration in another scope:

\begin{itemize}

\item When a name has \defnadj{external}{linkage},

the entity it denotes

can be referred to by names from scopes of other translation units or

from other scopes of the same translation unit.

\item When a name has \defnx{module linkage}{linkage!module},

the entity it denotes

can be referred to by names from other scopes of the same module unit\iref{module.unit} or

from scopes of other module units of that same module.

\item When a name has \defnadj{internal}{linkage},

the entity it denotes

can be referred to by names from other scopes in the same translation

unit.

\item When a name has \indextext{linkage!no}\defn{no linkage}, the entity it denotes

cannot be referred to by names from other scopes.

\end{itemize}