This came up in Help chat today, someone had previously been at +0 x0 and wanted to know how to return to that setting.
I confirmed this is the default setting when you have a character that has never altered their notoriety.
It is impossible to re-establish a setting of x0 as yourself x 0 would be equal to 0 enemies.
I don't know if this counts as a typo or a bug or what, but its confusing to new players and even to old players as there is effectively no difference between x0 and x1. It should, by default, be listed as x1 because, again, it isn't x0 as that would spawn an empty mission.
Just wanted this noted down somewhere if someone wants to peek at it, its a super minor change and not even a QoL, just something that occassionally causes confusion.