http://peach.ease.lsoft.com/scripts/wa.exe?S2=LSTOWN-L&m=LAST1

gives you the most recent message posted to LSTOWN-L.

http://peach.ease.lsoft.com/scripts/wa.exe?S2=LSTOWN-L&m=LAST1,LAST2

gives you the last two messages posted to LSTOWN-L.

http://peach.ease.lsoft.com/scripts/wa.exe?S2=LSTOWN-L&m=LAST1,LAST2,LAST3

gives you the last three messages posted to LSTOWN-L.

And so on.

(You're correct that this is not documented anywhere at present.)

Thanks,
--
Jacob Haller, Technical Support
L-Soft international, Inc
http://www.lsoft.com/