By Huw Williams
BBC news reporter
People start queuing more than an hour before events
There is a very odd phenomenon which you start to notice after spending any time at all in queues for the big sell-out events at Edinburgh's international book festival.
To get a decent seat, people start queuing anything up to an hour and a half before the sessions are scheduled to start.
But you can almost guarantee that perhaps 20 minutes before start time there will be a trickle of people who march confidently past the queue, up to the doors of the venue.
They clearly do not believe that all those people could possibly be waiting for the event they have come to see.
When they realise that - indeed - they all are, they have to do the Walk of Shame back to the end of the queue.
That can be right round the covered walkways of Charlotte Square, almost to the entrance.
Some stare at the ground, determined not to make eye contact with anyone.
Others adopt a shame-faced grin.
But in the past few days, I've noticed a slight variant.
I know there's a danger that this may sound ageist and sexist. It isn't meant to.
But it seems to me that Edinburgh's little old ladies seem to have worked out a new strategy.
Only the first few in line are guaranteed seats
There's a hard core who go to almost every event at the book festival.
And when they march to the front of the queue, they can be pretty confident that one of their friends will have got there early, and will invite them to join them.
Sometimes, it's even less subtle.
The other day I happened to be at the very front of the queue, sitting on a wooden pew placed there by the organisers.
One little old lady arrived carrying a plastic chair, borrowed from the gardens.
She put it down, in front of me.
She turned and flashed a winning smile.
"I'm sorry, but I can't sit on that hard wooden seat", she explained, "But of course I'll let you in first".
A few minutes later, one of her friends arrived, also carrying a plastic seat.
And a few minutes after that, there was a third little old lady. Also carrying her own chair.
It's so blatant, and so cleverly done, that it's hard to mind.
After all, why shouldn't old women wear purple?