Janet is quite right it is defacement.

Janet has a point: you borrow something on the implicit understanding that you will return it in the same condition.

One man's (woman's) defacement is another's improvement... ;)

Hold on - isn't the issue not the coincidence about who else borrowed the map for the same event but why has an LDWA member defaced the property of a local library. Not in our best tradition!

John,
It hadn't entered my head to find out who the previous borrower was. Not sure if your suggestion would work as a lot of lending and returning is done electronically these days so no dates are stamped. Also in these times of data protection etc. I don't think a Librarian would tell me this information.
Thinking about the coincidence it would only happen if the borrowed item was marked so I suppose it could happen lots of times and we would never know.
P.S. I enjoyed your photos and video - keep up the good work.
Mick

Michael & Heather, why not work out from 'return by' dates when it was borrowed in each year, then ask the librarian who had it on each occasion.
Norman, would it be a coincidence if it had happened to only one person in the past? ;-)

HI Michael I'm aware of it happening before for other events. But for it to happen to 2 people is indeed a strange co-incidence

I recently borrowed two OS maps from my library needed to navigate around the Herts Stroller last weekend. When I opened up the first one
I noticed the route had been marked out on it with little crosses at junctions and the check points were also marked. Not only that, but the paragraph numbers of the route description were also marked.Low and behold, when I opened up the second map for the other part of the route this was also marked in exactly the same way.Obviously somebody else from my area had borrowed the same two maps in the past for this event. As the event has only been held twice before in 2010 and 2012 I thought this to be a strange coincidence - or is it? It got me thinking has it ever happened to anybody else?

I'm not too sure how many maps county libraries hold for other areas, so would it be that unusual for the same two maps to be borrowed for the same event by different people in different years?