placecard etiquette

How do you word the place card?

Mr. & Mrs. Tom xxxx

What about engaged couples?

Mr. Tom xxx & Ms. Jane XXX

What if I don't know the person's last name, is

Mr. Tom xxx & Jane

acceptable?

What if I don't know the guest's name, can I write

Mr. Tom xxx & Guest

Sorry for all the questions
TIA!

This is what we're doing :

Married : Mr. and Mrs. John Smith
Engaged: Mr. John Smith and Ms. Jane Doe
Single: (same as engaged - FIND OUT THE GUESTS NAME)
i really dont think that you can say
Mr. John Smith and Jane


Good luck!!
-Jennifer