Picture posting is enabled for all :)
Sort of. Some crops like runner beans don't need it, since they don't have any significant diseases in the UK. Others need it badly as disease can build up in the soil. I'm always running out of space and having to break the rules, but I avoid growing anything on the same spot two years in a row if I can, and if I can't, it's going to be something like sweet corn that doesn't have disease problems.