What does %prec '.' mean here in yacc?

Question

notype_declarator:
      notype_declarator '(' parmlist_or_identifiers  %prec '.'
        { $$ = build_nt (CALL_EXPR, $1, $3, NULL_TREE); }

Anyone familiar with yacc rules?

Answer 1

It declares that the construct has the same precedence as the '.' operator, which have been specified earlier.