-Make sure the information in this file is current. Most notably, make sure it
-recommends a version of GNU M4 that is compatible with the latest Bison
-sources.
+Make sure the information in README is current. Most notably, make sure
+it recommends a version of GNU M4 that is compatible with the latest
+Bison sources.
+
+** Check copyright years.
+We update years in copyright statements throughout Bison once at the
+start of every year by running `make update-copyright'. However, before
+a release, it's good to verify that it's actually been run. Besides the
+copyright statement for each Bison file, check the copyright statements
+that the skeletons insert into generated parsers, and check all
+occurrences of PACKAGE_COPYRIGHT_YEAR in configure.ac.