[odinduty]

And what's the practical difference between minimaxir#1667 and minimaxir1667, other than there's no "minimaxir" with no numbers?

[minimaxir]

Numbers are allowed in the username (https://us.battle.net/support/en/article/700007) so using a pound as a delimiter is necessary to separate numbers at the end of a Battletag and the unique identifier.

[Dylan16807]

Unless you're hovering your mouse over them, it only shows minimaxir.