填空题
Invitations to very formal dinners may be engraved or written by hand in the third-person style. Less formally, they are written on notepaper or an informal note. The typeface is a matter of personal choice. For less formal occasion the attractive, decorated, preprinted invitations available at stationers and card stores are perfectly acceptable and practical.
Punctuation is used only when words requiting separation occur on the same line, and in such abbreviations as "R.S.V.P. ". The time is never given as nine-thirty, but as half after nine o'clock or half past nine o' clock.
If the event is to be given at one address and the hostess lives at another, her address should appear below the R. S. V. P., assuming that she wishes replies to go to her home.
If the party is formal, the phrase "black tie" or "white tie" appears in the lower fight-hand comer of the invitation.
Invitations should be issued between two and three weeks ahead of time, and they should be answered at once.
What does it mean if the phrase "black tie" appears in the lower right-hand comer of the invitation of a party
It means the party is （）