The message should include hosts' names, date, venue, time, and post-ceremony plans. Note that the recipient matters, e.g., a sister wedding invitation message is less formal than one for a colleague.

When contemplating whether to include ... invitation—even if we know the person can not attend. Invitations, whether to casual events like a luncheon or to something as memorable as a wedding ...

DEAR MISS MANNERS: My soon-to-be husband and I are planning our wedding, and are having a disagreement on how to address the invitations. We have agreed to abide by your decision. He says that ...