A Chonáin,

This was recently discussed on the IRTRAD-L list. Here's the URL for the explanatory message there:

http://listserv.heanet.ie/cgi-bin/wa?A2=ind9911&L=irtrad-l&F=&S=&P=29552

I hope that works, I don't know how to do a 'blue clicky thingy.'

-- Áine