| BreakIterator | Implements methods for finding the location of boundaries in text |
| Calendar | Calendar is an abstract base class for converting between a UDate object and a set of integer fields such as YEAR, MONTH, DAY, HOUR, and so on |
| CanonicalIterator | This class allows one to iterate through all the strings that are canonically equivalent to a given string |
| CharacterIterator | Abstract class that defines an API for iteration on text objects |
| ChoiceFormat | ChoiceFormat converts between ranges of numeric values and string names for those ranges |
| CollationElementIterator | Used as an iterator to walk through each character of an international string |
| CollationKey | Collation keys are generated by the Collator class |
| Collator | The Collator class performs locale-sensitive string comparison |
| CollatorFactory | A factory, used with registerFactory, the creates multiple collators and provides display names for them |
| DateFormat | DateFormat is an abstract class for a family of classes that convert dates and times from their internal representations to textual form and back again in a language-independent manner |
| DateFormatSymbols | DateFormatSymbols is a public class for encapsulating localizable date-time formatting data -- including timezone data |
| DecimalFormat | Concrete class for formatting decimal numbers, allowing a variety of parameters, and localization to Western, Arabic, or Indic numbers |
| DecimalFormatSymbols | This class represents the set of symbols needed by DecimalFormat to format numbers |
| DictionaryBasedBreakIterator | A subclass of RuleBasedBreakIterator that adds the ability to use a dictionary to further subdivide ranges of text beyond what is possible using just the state-table-based algorithm |
| FieldPosition | FieldPosition is a simple class used by Format and its subclasses to identify fields in formatted output |
| Format | Base class for all formats |
| Formattable | Formattable objects can be passed to the Format class or its subclasses for formatting |
| ForwardCharacterIterator | Abstract class that defines an API for forward-only iteration on text objects |
| GregorianCalendar | Concrete class which provides the standard calendar used by most of the world |
| ICULayoutEngine | This is a wrapper class designed to allow ICU clients to use LayoutEngine in a way that is consistent with the rest of ICU |
| Locale | A Locale object represents a specific geographical, political, or cultural region |
| MessageFormat | A MessageFormat produces concatenated messages in a language-neutral way |
| Normalizer | C++ API: Unicode Normalization |
| NumberFormat | Abstract base class for all number formats |
| NumberFormatFactory | A NumberFormatFactory is used to register new number formats |
| ParsePosition | ParsePosition is a simple class used by Format and its subclasses to keep track of the current position during parsing |
| RegexMatcher | Class RegexMatcher bundles together a reular expression pattern and input text to which the expression can be applied |
| RegexPattern | Class RegexPattern represents a compiled regular expression |
| Replaceable | Replaceable is an abstract base class representing a string of characters that supports the replacement of a range of itself with a new string of characters |
| ResourceBundle | A class representing a collection of resource information pertaining to a given locale |
| RuleBasedBreakIterator | A subclass of BreakIterator whose behavior is specified using a list of rules |
| RuleBasedCollator | Simple implementation of Collator, using data-driven tables |
| RuleBasedNumberFormat | C++ API: RuleBasedNumberFormat |
| SearchIterator | SearchIterator is an abstract base class that provides methods to search for a pattern within a text string |
| SimpleDateFormat | SimpleDateFormat is a concrete class for formatting and parsing dates in a language-independent manner |
| SimpleNumberFormatFactory | A NumberFormatFactory that supports a single locale |
| SimpleTimeZone | SimpleTimeZone is a concrete subclass of TimeZone that represents a time zone for use with a Gregorian calendar |
| StringCharacterIterator | A concrete subclass of CharacterIterator that iterates over the characters (code units or code points) in a UnicodeString |
| StringEnumeration | Base class for 'pure' C++ implementations of uenum api |
| StringSearch | StringSearch is a SearchIterator that provides language-sensitive text searching based on the comparison rules defined in a RuleBasedCollator object |
| SymbolTable | An interface that defines both lookup protocol and parsing of symbolic names |
| TimeZone | TimeZone represents a time zone offset, and also figures out daylight savings |
| Transliterator | Transliterator is an abstract class that transliterates text from one format to another |
| Transliterator::Token | A context integer or pointer for a factory function, passed by value |
| UCharCharacterIterator | A concrete subclass of CharacterIterator that iterates over the characters (code units or code points) in a UChar array |
| UCharIterator | C API for code unit iteration |
| UConverterFromUnicodeArgs | The structure for the fromUnicode callback function parameter |
| UConverterToUnicodeArgs | The structure for the toUnicode callback function parameter |
| UDataInfo | UDataInfo contains the properties about the requested data |
| UFieldPosition | A struct representing a range of text containing a specific field ICU 2.0 |
| UMemory | UMemory is the common ICU base class |
| UnicodeFilter | UnicodeFilter defines a protocol for selecting a subset of the full range (U+0000 to U+10FFFF) of Unicode characters |
| UnicodeFunctor | UnicodeFunctor is an abstract base class for objects that perform match and/or replace operations on Unicode strings |
| UnicodeMatcher | UnicodeMatcher defines a protocol for objects that can match a range of characters in a Replaceable string |
| UnicodeReplacer | UnicodeReplacer defines a protocol for objects that replace a range of characters in a Replaceable string with output text |
| UnicodeSet | A mutable set of Unicode characters and multicharacter strings |
| UnicodeSetIterator | UnicodeSetIterator iterates over the contents of a UnicodeSet |
| UnicodeString | UnicodeString is a string class that stores Unicode characters directly and provides similar functionality as the Java String and StringBuffer classes |
| UObject | UObject is the common ICU "boilerplate" class |
| UParseError | A UParseError struct is used to returned detailed information about parsing errors |
| UReplaceableCallbacks | A set of function pointers that transliterators use to manipulate a UReplaceable |
| USerializedSet | A serialized form of a Unicode set |
| UTransPosition | Position structure for utrans_transIncremental() incremental transliteration |
