In C# 7.2, we extend the set of places that digit separators (the underscore character) can appear in integral literals. [Beginning in C# 7.0, separators are permitted between the digits of a literal](../csharp-7.0/digit-separators.md). Now, in C# 7.2, we also permit digit separators before the first significant digit of a binary or hexadecimal literal, after the prefix.