[Zope] The Let Tag How-To?

Sorry for bothering you about this, but I've been trying to go through your Let Tag howto. I'm doing this on 2.1.4, and I get the feeling that some features have deprecated. Your example: <dtml-let name="bob" relation="uncle"> <dtml-var name> is your <dtml-var relation> </dtml-let> doesn't work for me; I have to add an additional set of quotes to make it work: <dtml-let name="'bob'" relation="'uncle'"> <dtml-var name> is your <dtml-var relation> </dtml-let> Can anyone explain what changed and why? Quotation itself feels clumsy; is there any way to escape-sequence quotes? In nested DTML/SQL expressions, being unable to use \" seems awkward. Thanks for any help.