Site disruption at the weekend

At some point this weekend, probably on Saturday afternoon, UK time, I’ll be upgrading the software that powers this (and other) sites. This will mean that first I’ll hide all the forms for posting annotations (so nothing is lost or broken in the switch-over) and then things might look a bit odd if I break something. Hopefully it won’t take too long and I’ll post here again when it’s all up and running.