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What do the flags of West Virginia and Wyoming contain
that no other U.S. state flags do?
Here is the ANSWER. 

ANSWER:

A THICK BORDER AROUND ALL FOUR OUTER EDGES.

See 
http://en.wikipedia.org/wiki/File:Flag_of_West_Virginia.svg
and 
http://en.wikipedia.org/wiki/File:Flag_of_Wyoming.svg

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