NumberingSymbol
Any symbol that appears in a numbering format. For example, in the format 1.A.a:
1is a DecimalNumberingSymbol, which counts1, 2, 3, ....is a NumberingFixedSymbolAis an uppercase AlphaNumberingSymbol, which countsA, B, C, ....is a NumberingFixedSymbolais a lowercase AlphaNumberingSymbol, which countsa, b, c, ...