I have found that Char.IsLetter() returns True for the masculine ordinal character, described at http://en.wikipedia.org/wiki/Ordinal_indicator. The Char.GetUnicodeCategory() function reports it is a LowercaseLetter, but I would think it should be reported as a symbol. I have tested this in both .NET 4.0 and .NET 4.5. Of course, this could be "by design"; I'll let you respond.
Visual Studio/Team Foundation Server/.NET Framework Tooling Version
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