Honour or Honor on Your Wedding Invitation?
For the longest time, I assumed using "request the honour of your presence" was just the fancier version of the word. Although it is, there is also actual reason behind why you might choose to use the spelling "honour" over "honor" on the request line of your invitation besides the fact that it just looks pretty.
It is customary to use "honour" if you are saying "i do" in a church or religious house of worship. According to Crane and Co., the word "honour" is used to show respect and deference to God when your ceremony is held in a place of worship on sanctified ground.
As one of faith, I love that one word, just by spelling it a smidge differently, can show enormous respect and submission to the God of the universe. However, I believe that God is everywhere, and even if the ground you stand on to say your vows before the Lord is in your parent's backyard or at a garden wedding venue, it is sanctified, because He is present.
For other venue locations outside of a religious location, using the word "honor" is equally beautiful and acceptable. Also, using "request the pleasure of your company" is equally acceptable as well. Determining which one to use just comes down to your personal preference.
For more casual weddings and invitations, you might choose to use the wording "invite you to celebrate the marriage of," which implies this will be a beautiful, but casual celebration. Maybe the wedding is a small and cozy event as opposed to a large and elaborate ceremony.
Remember, etiquette is just a guide to follow. Sixty years ago, etiquette was like some sort of unspoken law among women. (and maybe it still is with some) Nowadays, is it completely acceptable to word your invitation and plan your wedding to what fits you and your partner's personality while using modern etiquette as a guide. Although etiquette is not an much law as it used to be, the main rule of thumb is to ensure whatever you do or say does not offend your guests. Just put yourself in their shoes.
You can also check out the modern version of Emily Post's Wedding Etiquette book to help you.
Show who you are as a couple in every aspect of your wedding, and that will be timeless. :)