The note starts out "Do not (do x) unless you're not (doing y)". This is confusing. I believe this means "If you are (doing y), you may (do x)". If so, please write it so. If not, please write what you do mean.

After thinking about it, "Only (do x) if you are (doing y)" might be a better rewrite. Or "You may (do x) only if you are (doing y)"

Change "be mindful of escaping" to the more direct "escape". Perhaps give a list of possible special characters.

I agree that this seems a bit verbose for reference documentation. Perhaps there should be a separate PyWiki entry or HowTo doc. That could, for instance, list the special characters for various shells if they are not all the same.