I'd like to know whether the keyword object is used in various other
ways, except named optional parameters.  If it is only for the named
optional parameters and the named optional parameters can be
implemented in other ways without introducing a new data type, I
wonder it is so valuable to add it to innate self-evaluating objects
(such as number, string, character, boolean).

Although it matters little for symbols to be used as parameters of a
procedure, I want to know how frequently simple symbols are used as
parameters of procedures in Scheme progamming like `buy'.

For named parameters to be visually different from other parameters,
I think
(buy 'apple 'day 'low '(price 71.89) '(qty 1000))
or
(buy 'apple 'day 'low ##price## 71.89 ##qty## 1000)
would be better.

--
Joo ChurlSoo