Prototypes, /COPY and LIKE()

Okay, I'm running into an issue.  I've gotten very good about creating
modules and using /COPY to separate the external prototypes for
procedures.  This works wonderfully except for one specific situation.

Often, I like to pass a database field as a parameter.  I've learned
over the years that the best way to define such a field is by doing a
LIKE define against the actual database field.  For example:

d SccIOKWClear    pr                                       
d   ID                                like(KWDFID) value 
d   Format                            like(KWFMT ) value

This function clears all the records from the file with the two key
fields specified.  Works like a champ, provided I have defined KWDFID
and KWFMT. However, with a /COPY prototype, there's no simple way of
importing the database definitions in order to do a LIKE define against
them.

I could include an externally described data structure, but now I'm
looking at wasted storage and possible name space collisions.  Thus my
dilemma.

My current thinking is to use a based external DS with a prefix.  This
would "waste" only the space for a pointer, thus:

d __SCCKW       e ds                  extname(SCCKW) based(__)
prefix(__)
d SccIOKWClear    pr                                       
d   ID                                like(__KWDFID) value 
d   Format                            like(__KWFMT ) value

(The double underscore is just an idea; I could just as easily use a
double @ or something else to try and minimize collisions.)

Any comments?

Joe