Something I was wondering a few days ago is which is better to avoid duplicate names, [first initial][surname] or [forename][surname initial]eg: pgraham@ycombinator.com vs paulg@ycombinator.com.
40% of Vietnamese people have the surname Nguyễn, if you use the first initial + last name system then by the birthday paradox, there is a 50% chance of a first initial collision with 6.5 Nguyễns in your organisation. That means that if you have more than about 16 Vietnamese employees, you have a 50% chance of an email id collision. It's actually higher than that because Vietnamese-American first names are often English, so the distribution of first initials is not evenly distributed.