Comments and Registering

I’m afraid I have had to change the default for posting comments to the blog. The site has been subject to a sustained spam attack for a few days now. As a result, I have had to stop open comments for each blog post. For at least the next couple of weeks, comments can only be made if you register. Sorry about this. I’ll try to change it back again once things quieten down. Any useful comments for dealing with this can be sent to me using the contacts tab at the top of the page. Thanks for your patience.