<a href="#Function_declarations">function</a>,
<a href="#Labeled_statements">label</a>, or
<a href="#Import_declarations">package</a>.
Every identifier in a program must be declared.
No identifier may be declared twice in the same block, and
no identifier may be declared in both the file and package block.
</p>

<p>
The <a href="#Blank_identifier">blank identifier</a> may be used like any other identifier