The overwhelmingly common authored border is the SAME stroke on several edges — a boxed range
is four identical edges, and listing top thick X · left thick X · bottom thick X · right thick X says one fact four times. Edges sharing a stroke collapse into one part: all four
outer edges become outline, any other run lists its edges (top+bottom thin). Only
genuinely distinct strokes produce distinct parts — which is what makes the multi-line form
(one part per line) worth printing.
The border as a list of parts, identical edges grouped.