Constructs are only appropriate for certain events (a range of convenience). Some ranges are large and others are smaller. The range covers the applicability of the construct.
Example: Basset hounds can be spotted yellow, brown, black, or combo colored. That is their range (yellow but not brown, black, or combo spots; brown but not yellow, black, or combo spots, etc.). This range does not apply to chow mixes. They are not spotted. On the other hand, chow tongues can be pink, purple, or combo colored. This range does not apply to basset hounds.