What is a Tissue Meeting?

I've been hearing whispers about a new type of trendy meeting. It's called the 'Tissue Meeting'. Now as I'm the type of person who gets his nose wipes from the toilet roll I wondered what on earth this could mean. Is office space so expensive that people are expected to hold meetings in the WC. And would that be in a cubical or by the taps.
I've known a few advertising types in my time who have a penchant for meeting in the cubicals for one reason or another. But I don't recall anyone using the term 'tissue meeting' to arrange such a rendezvous. "Hey. I've got some great gear. Fancy a tissue meeting in the toilet?"

There's only one reason why someone would define a meeting as a'Tissue Meeting'. That's because the people who organise one have got their heads so far up their arses - that they need something to wipe away all the crap.