Comment policy

I've been impressed by the comment policy at Paul Krugman's blog, so I'm going to borrow it here, with a few tweaks:

• No spam
• No comments irrelevant to the post or ongoing comment discussion
• No ad hominem or obscenities
• First time you comment, it's held until I can approve it.
• No comments that stretch beyond roughly a screen
• No consecutive comments to get around the item above

I reserve the right to delete without notice any comment that violates the above.