@command{install} creates each @var{directory} and any missing parent
directories. Parent directories are created with mode
@samp{u=rwx,go=rx} (755), regardless of the @option{-m} option or the
-current umask.
+current umask. @xref{Directory Setuid and Setgid}, for how the
+set-user-ID and set-group-ID bits of parent directories are inherited.
@end itemize
@cindex Makefiles, installing programs in
which can be either an octal number, or a symbolic mode as in
@command{chmod}, with @samp{a=} (no access allowed to anyone) as the
point of departure (@pxref{File permissions}).
-The default mode is @samp{u=rwx,go=rx,a-s} (0755)---read, write, and
+The default mode is @samp{u=rwx,go=rx,a-s}---read, write, and
execute for the owner, read and execute for group and other, and with
set-user-ID and set-group-ID disabled.
+This default is not quite the same as @samp{755}, since it disables
+instead of preserving set-user-ID and set-group-ID on directories.
+@xref{Directory Setuid and Setgid}.
@item -o @var{owner}
@itemx --owner=@var{owner}
is created. As a @acronym{GNU} extension, @var{mode} may also mention
special mode bits, but in this case there may be a temporary window
during which the directory exists but its special mode bits are
-incorrect.
+incorrect. @xref{Directory Setuid and Setgid}, for how the
+set-user-ID and set-group-ID bits of directories are inherited unless
+overridden in this way.
@item -p
@itemx --parents
@cindex parent directories, creating
Make any missing parent directories for each argument. The file permission
bits of parent directories are set to the umask modified by @samp{u+wx}.
+@xref{Directory Setuid and Setgid}, for how the set-user-ID and
+set-group-ID bits of parent directories are inherited.
Ignore arguments corresponding to existing directories, and do not
change their file mode bits.