| FixedLengthString | Defines a String with a fixed length. |
| FormattableString | Represents a formattable String. |
| GroupingCharsInfo | Defines the characters used for an aperture and closure of an string. |
| GroupingInfo | Defines the info about enclosed and opened groups of chars in a String. |
| UnicodeCharacterMaps | Provides access to predefined alphabetic and alphanumeric character maps for a range of Unicode character sets. |
| UtilString | Contains String related utilties. |
| UtilStringWordLists | A class that exposes common RegEx patterns. |
| BoxDrawingStyle | Defines the characters used to draw the sides and corners of a box. |
| CharDiff | Represents the difference state between two characters in two different strings (Original String, Current String). |
| CharDiffState | Specifies a difference state of a character in a string. |
| StringCase | Specifies a string case. |
| StringDirection | Specifies the direction to read a String. |
| UnicodeAlphabeticCharacterSets | Specifies a Unicode alphabetic character set. This enum is used by ConvertToUnicodeLetters(String, UnicodeAlphabeticCharacterSets) function. |
| UnicodeAlphanumericCharacterSets | Specifies a Unicode alphanumeric character set. This enum is used by ConvertToUnicodeLetters(String, UnicodeAlphabeticCharacterSets) function. |
| VerticalFlipTextMode | Specifies how the text should be flipped when using FlipTextVertically(String, VerticalFlipTextMode, Char) function. |