Explaining mixed marriage in Ireland

"Mixed marriage" strictly means a marriage contracted between a Christian and a non-Christian, but it has come to mean, particularly in Ireland, a marriage contracted between a Roman Catholic and another Christian from the Protestant denomination.
Strictly this should be called an Interchurch marriage, for it is a marriage between two Christians who belong to different denominations. We should not forget that this term would include Church of Ireland-Presbyterian marriages and other inter-Protestant marriages. While it is more correct to use the term "Interchurch marriage" for those marriages where both partners are deeply committed to their own churches the term "mixed marriage" is readily understood in Ireland.
However, it must be remembered that the original meaning of the term - a marriage between a Christian and a non-Christian - still applies, and these marriages still occur in Ireland today. Examples of Jewish-Christian and Muslim-Christian marriages are known and can pose different challenges.

so...what do you think about explaining???