(ignore {var | (function fn)}*)
(ignorable {var | (function fn)}*)
The ignore and ignorable declarations refer to for-value references to variable bindings for the vars and to function bindings for the fns.
An ignore declaration specifies that for-value references to the indicated bindings will not occur within the scope of the declaration. Within the scope of such a declaration, it is desirable for a compiler to issue a warning about the presence of either a for-value reference to any var or fn, or a special declaration for any var.
An ignorable declaration specifies that for-value references to the indicated bindings might or might not occur within the scope of the declaration. Within the scope of such a declaration, it is not desirable for a compiler to issue a warning about the presence or absence of either a for-value reference to any var or fn, or a special declaration for any var.
When not within the scope of a ignore or ignorable declaration, it is desirable for a compiler to issue a warning about any var for which there is neither a for-value reference nor a special declaration, or about any fn for which there is no for-value reference.
Any warning about a "used" or "unused" binding must be of type style-warning, and may not affect program semantics.
The stream variables established by
with-open-file,
with-open-stream,
with-input-from-string,
and with-output-to-string,
and all iteration variables are, by definition, always "used".
Using (declare (ignore v)),
for such a variable v has unspecified consequences.