You're invited. Now what?

Nearly everything written about weddings is written for the couple. But a wedding has one couple and a hundred and forty guests, and the guests are the ones lying awake wondering whether their dress is too white.

So these are for you. Every page starts with the answer — yes, no, or it depends and here's on what — and explains itself underneath, for when you want to know why.

The three that matter most

• Don't wear white. It is the one guest rule that genuinely still holds, and it includes ivory, cream, champagne and anything that photographs white under a flash.
• RSVP by the date, even if it's a no. About a fifth of guests miss it at every wedding, which means the couple spends a week chasing people while finalising catering numbers.
• Bring only the people named on the invitation. Venues have hard capacity limits and catering is charged per head. An extra guest is a real cost, not a formality.

If the wedding isn't a Western one

A lot of guest advice assumes a white dress, a church and a seated dinner. If you have been invited to a Chinese, Indian, Nigerian, Jewish, Persian or any other wedding whose customs you do not know, the colours to avoid and the things that will happen are genuinely different — red is the bride's colour at some, white means mourning at others.

We have 45 pages on wedding traditions describing what actually happens at them, written for people who want to turn up and get it right.