? Syntax curiosity

I realize that there IS a better way to write the syntax given in this specific example; however, I am curious about something some pseudo-code that I just looked at:

where zipcode likeness in
( '[0-9][0-9][0-9][0-9][0-9]',
  '[0-9][0-9][0-9][0-9][0-9]-[0-9][0-9][0-9][0-9]',
  '[0-9][0-9][0-9][a-z][a-z][a-z]'
)

I doubt that I am the only one who has ever thought about something like this kind of syntax, but would syntax similar to this be troublesome?

Kent