The council puts the bright yellow ones up often, but never removes them. Residents and local businesses, schools etc tape them to trees, posts, fences etc and never remove them. All of them look tatty after a while, but the people who put them up never think of that. So, if you do put up a notice saying 'happy birthday Marjorie' or 'baby yoga classes this Sunday', please take them down afterwards. Or, if you are like me, rip them down yourself. You can also post them back to the offender, like St John's and St Clement's school, whose tatty laminates for their Christmas fair of five or more weeks ago are still hanging around.