public PartRule() { var prefixes = new[] { "pt", "part" }; RB = new ReBulk(name: "part").Options(RegexOptions.IgnoreCase) .Regex(RegexUtils.BuildOrPattern(prefixes, "prefixes") + @"-?(?<part>" + RegexUtils.BuildOrPattern(new[] { Regexes.digital_numeral, Regexes.roman_numeral }, "partnumber") + @")") .Then(x => IsNumeric(x)); }