I had a little discussion in the numista coin catalogue section, about the 1/3 farthing which were legal tender in Malta and have never been legal tender in UK.
I came up with the following addition today, maybe its an option, this can also be done with Euro coins by saying: Legal tender in EU. By used in coins.

With euro coins you could do this

Another reason why: The Netherlands minted money abroad money during the war for the colonies. The coins were legal tender abroad but also in NL, so there could be added also used in, or also legal tender in or only used in. Because some collectors see the dutch coins which were minted for Suriname as Suriname coins, or the 1/3 farthing where the discion was about as a Maltese coin.