@code{clear-string}:
@defun clear-string string
-This clears the contents of @var{string} to zeros.
-It may also change @var{string}'s length and convert it to
-a unibyte string.
+This makes @var{string} a unibyte string and clears its contents to
+zeros. It may also change @var{string}'s length.
@end defun
@need 2000