From Kornel [1]:
Exporting to 2.3 format and exporting from the exported differ in extra lines and
in changed sequence of 2 lines at begin.
$ diff doc/fr/UserGuide.23.lyx fr/UserGuide.23.23.lyx
[1] https://www.mail-archive.com/lyx-devel@lists.lyx.org/msg218252.html
# (we only use "recent" lyx2lyx roundtrip to test compilation.
export/doc/de/UserGuide_lyx2(2|3)
+# (https://www.mail-archive.com/lyx-devel@lists.lyx.org/msg218252.html)
+# from Kornel:
+# Exporting to 2.3 format and exporting from the exported differ in extra lines and
+# in changed sequence of 2 lines at begin.
+#
+# $ diff doc/fr/UserGuide.23.lyx fr/UserGuide.23.23.lyx
+export/doc/fr/UserGuide_lyx2(2|3)
+
# ===========================================
Sublabel: special