Illegal to Deface Money?

Are you goi ng to get in trouble for writing or drawing on your dollar bills? What about dissolving the face of a coin in the science lab? Here's the scoop on whether it is illegal to deface money:

It is indeed illegal to deface money, and here is the specific wording of the law:

"Whoever mutilates, cuts, defaces, disfigures, or perforates, or
unites or cements together, or does any other thing to any bank bill,
draft, note, or other evidence of debt issued by any national banking
association, or Federal Reserve bank, or the Federal Reserve System,
with intent to render such bank bill, draft, note, or other evidence
of debt unfit to be reissued, shall be fined under this title or
imprisoned not more than six months, or both."

My understanding of this, though, is since it talks specifically about defacing with intent to make the bill unfit to reuse, it only applies to actually ripping up the bills or other actions that make it unusable, not simply writing or drawing on it in a way that leaves the dollar bill intact, and doesnt obscure which kind of bill it is. For more info see below:

Illegal to Deface Money?
google answers

Defacing US currency is indeed illegal. Defacement of currency in such
a way that it is made unfit for circulation comes under the
jurisdiction of the United States Secret Service...

Illegal to Deface Money?