Other ID Start refers to characters that, although not part of the typical ID Start category, can still initiate identifiers, like variable names in programming languages. This broadens the range of characters available for creating meaningful identifiers.
As of Unicode Version 15.0.0, there are 2 different Other ID Start.
No, the Other ID Start property is a binary property, which means it can only have one of two values: Yes or No. There are no specific values or levels associated with it.