Gnulib provides copies of the GNU GPL, GNU LGPL, and GNU FDL licenses
in Texinfo form. (The master location is
http://www.gnu.org/licenses/). These Texinfo documents do not
have any node names and structures built into them; for your manual,
@include them in an appropriate
The conventional name for the GPL node is ‘Copying’ and for the FDL ‘GNU Free Documentation License’. The LGPL doesn't seem to have a conventional node name.
Of course the license texts themselves should not be changed at all.