The number is optional, but if you're wondering "what number should I use?"
Generic Occasion - Inspired by the timeless Chanel No.5, going with 5 is always a classic!
Mother's Day - No.1 MUM, or drop the number and just have MUM Happy Mother's Day etc
Teacher thank you - No.1! You'll be sure your child is the teachers pet
Valentine's Day - No.1 Love, or drop the number and just have a NAME Happy Valentine's Day etc
Weddings - the abbreviated year of marriage
Matching Bride & Groom - No.1 Bride and No.1 Groom of course
Bridal party proposals - the year of the upcoming wedding, or No.1 Bridesmaid, Maid of Honour etc
Engagements - the year of engagement or the year of the upcoming wedding
Baby - first, second, third child etc; or use their abbreviated birth year
Birthdays - the age being celebrated, ie 1, 16, 18, 21, 30, 40, 50, 60 etc
Anniversary - the number of years being celebrated, or the abbreviated year of marriage
Business - the street address shop number or go for No.1 'coz you're the best in the biz!
Family Surname - the number of family members