>> Also, documented a nasty quirk of :=
>> [...]
>>  Normally, expansion is not done until the variable is referenced.
>> +.Em NOTE :
>> +References to undefined variables are
>> +.Em not
>> +expanded.  This can cause problems when variable modifiers are used.

>Is that really desired behaviour that should be documented?  It looks to
>me like a bug that should be fixed.

That's what I was planning to do yesterday.  But the code and comments
show that the behavior is very deliberate (other than the bit with 
modifiers ;-), so I figured changing it was likely to do more harm than
good.  I did wonder whether an undefined variable
that is being referenced with modifiers, should be handled differently
bug again that just makes things more complex.

So, since I was punting, documenting the kwirk is the next best thing.

--sjg