Indicates that the numeric string represents a hexadecimal value. Valid hexadecimal values include the numeric digits 0-9 and the hexadecimal digits A-F and a-f. Strings that are parsed using this style cannot be prefixed with "0x" or "&h". A string that is parsed with the NumberStyles.AllowHexSpecifier style will always be interpreted as a hexadecimal value. The only flags that can be combined with NumberStyles.AllowHexSpecifier are NumberStyles.AllowLeadingWhite and NumberStyles.AllowTrailingWhite. The System.Globalization.NumberStyles enumeration includes a composite style, NumberStyles.HexNumber, that consists of these three flags.