Recently the coinage has had limited redemption policies enforced.
Honestly I have no idea what that means exactly.
What it means is that, while the coins were originally issued as legal tender and technically they still are, the Marshall Islands government has passed laws forbidding large quantities of them to be imported, used in transactions or deposited in banks.
The Marshall Islands made the mistake of putting too high a face value on their coins. Well, they were persuaded into doing so by the private mints that issued their coins under license. It was great for the mints that sold them, because they could justify charging high prices, And the Marshall Islands government hopefully got it's share of the seigniorage, too, but collector demand for them is virtually nonexistent - the resale value plummeted to scrap metal / bullion value, well below the face value.
"Bullion tourists" were buying up suitcase-fulls of Marshall Islands coins in America or Europe for well below face value, then travelling to the Marshall Islands and banking them. If you brought enough coins with you, you could make a profit on the trip, and get a nice free island holiday to boot. Meanwhile, the Marshall Islands government would be stuck with a pile of useless, overvalued, circulated "collector coins" that nobody wanted. All they could do is sell them for their scrap/bullion value, and they might end up back in the hands of the bullion tourists if they didn't go to the extra expense of defacing them. They couldn't afford to continue to dispose of them at a loss. Hence, the restrictions.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis