&optionalpackage → <no values>
&optionalpackage → symbols
For apropos, as each such symbol is found, its name is printed on standard output. In addition, if such a symbol is defined as a function or dynamic variable, information about those definitions might also be printed.
For apropos-list, no output occurs as the search proceeds; instead a list of the matching symbols is returned when the search is complete.
Because a symbol might be available by way of more than one inheritance path, apropos might print information about the same symbol more than once, or apropos-list might return a list containing duplicate symbols.
Whether or not the search is case-sensitive is implementation-defined.
apropos is also affected by *standard-output*.