And you can do exactly the same thing with a GFDL work. For example,
| A copy of the license is can be found at | http://www.gnu.org/licenses/fdl.txt
instead of:
| A copy of the license is included in the section entitled ``GNU | Free Documentation License.''
The GFDL seems to prohibit that. Both verbatim and modified copies are supposed to include a full copy of the actual license text, not just a reference to it. See Sec. 2 para. 1 and Sec. 4 part H of the GFDL.
I was thinking of the new GFDL (when it is out), not the old one. See section 6a. But you are ofcourse right that GFDL 1.2 does not allow this.
The Creative Commons license doesn't have a similar requirement; it doesn't say that you need to include a copy of the actual license text in order to distribute.
I re-read the CC-by-SA license, and I stand corrected.