Ref-1:
"The use of "commonwealth" in the name Commonwealth of Kentucky doesn't have any particular significance — it means the same thing as "state" and was commonly used in the eighteenth century."

Ref-2:
"There are two types of notary public in Kentucky: state at large and special commission. A notary public state at large witnesses document signings and other acts within the state of Kentucky, but the actual documents can be recorded in other states. Special commission notaries, who require an appointment by the governor of Kentucky, can notarize documents within or outside the state, but documents can only be recorded in Kentucky."


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Note added at 14 mins (2012-09-17 10:08:40 GMT)
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Ref-2:
http://www.ehow.com/about_6668731_kentucky-notary-public-inf...