examine the files that don't have copyright notices. Inspect the
results for plausibility, then commit them.
+A few known problems with the build-aux/update-copyright script:
+
+ . it doesn't update config.bat and etc/tutorials/TUTORIAL.he because
+ the "Copyright" statement begins in these two files after a prefix
+ that is more than 5 characters long
+ . it doesn't update the second Copyright notice, the one that gets
+ output into PDF and PS, in etc/refcards/ru-refcard.tex
+ . it doesn't update etc/refcards/gnus-refcard.tex because its
+ Copyright statement has a non-standard format
+
+These files need to be updated by hand.
+
You should also run the etags test suite in test/manual/etags/. It
will most probably fail because the contents of the test files changes
due to copyright years update, so you need to move each ETAGS and