Here is a list of all documented files with brief descriptions:
[detail level 123]
  common | |
   unicode | |
   appendable.h | C++ API: Appendable class: Sink for Unicode code points and 16-bit code units (char16_ts) |
| brkiter.h | C++ API: Break Iterator |
| bytestream.h | C++ API: Interface for writing bytes, and implementation classes |
| bytestrie.h | C++ API: Trie for mapping byte sequences to integer values |
| bytestriebuilder.h | C++ API: Builder for icu::BytesTrie |
| caniter.h | C++ API: Canonical Iterator |
| casemap.h | C++ API: Low-level C++ case mapping functions |
| char16ptr.h | C++ API: char16_t pointer wrappers with implicit conversion from bit-compatible raw pointer types |
| chariter.h | C++ API: Character Iterator |
| dbbi.h | C++ API: Dictionary Based Break Iterator |
| docmain.h | (Non API- contains Doxygen definitions) |
| dtintrv.h | C++ API: Date Interval data type |
| edits.h | C++ API: C++ class Edits for low-level string transformations on styled text |
| enumset.h | C++: internal template EnumSet<> |
| errorcode.h | C++ API: ErrorCode class intended to make it easier to use ICU C and C++ APIs from C++ user code |
| filteredbrk.h | C++ API: FilteredBreakIteratorBuilder |
| icudataver.h | C API: access to ICU Data Version number |
| icuplug.h | C API: ICU Plugin API |
| idna.h | C++ API: Internationalizing Domain Names in Applications (IDNA) |
| localebuilder.h | C++ API: Builder API for Locale |
| localematcher.h | C++ API: Locale matcher: User's desired locales vs |
| localpointer.h | C++ API: "Smart pointers" for use with and in ICU4C C++ code |
| locdspnm.h | C++ API: Provides display names of Locale and its components |
| locid.h | C++ API: Locale ID object |
| messagepattern.h | C++ API: MessagePattern class: Parses and represents ICU MessageFormat patterns |
| normalizer2.h | C++ API: New API for Unicode Normalization |
| normlzr.h | C++ API: Unicode Normalization |
| parseerr.h | C API: Parse Error Information |
| parsepos.h | C++ API: Canonical Iterator |
| platform.h | Basic types for the platform |
| ptypes.h | C API: Definitions of integer types of various widths |
| putil.h | C API: Platform Utilities |
| rbbi.h | C++ API: Rule Based Break Iterator |
| rep.h | C++ API: Replaceable String |
| resbund.h | C++ API: Resource Bundle |
| schriter.h | C++ API: String Character Iterator |
| simpleformatter.h | C++ API: Simple formatter, minimal subset of MessageFormat |
| std_string.h | C++ API: Central ICU header for including the C++ standard <string> header and for related definitions |
| strenum.h | C++ API: String Enumeration |
| stringoptions.h | C API: Bit set option bit constants for various string and character processing functions |
| stringpiece.h | C++ API: StringPiece: Read-only byte string wrapper class |
| stringtriebuilder.h | C++ API: Builder API for trie builders |
| symtable.h | C++ API: An interface that defines both lookup protocol and parsing of symbolic names |
| ubidi.h | C API: Bidi algorithm |
| ubiditransform.h | C API: Bidi Transformations |
| ubrk.h | C API: BreakIterator |
| ucasemap.h | C API: Unicode case mapping functions using a UCaseMap service object |
| ucat.h | C API: Message Catalog Wrappers |
| uchar.h | C API: Unicode Properties |
| ucharstrie.h | C++ API: Trie for mapping Unicode strings (or 16-bit-unit sequences) to integer values |
| ucharstriebuilder.h | C++ API: Builder for icu::UCharsTrie |
| uchriter.h | C++ API: char16_t Character Iterator |
| uclean.h | C API: Initialize and clean up ICU |
| ucnv.h | C API: Character conversion |
| ucnv_cb.h | C API: UConverter functions to aid the writers of callbacks |
| ucnv_err.h | C API: UConverter predefined error callbacks |
| ucnvsel.h | C API: Encoding/charset encoding selector |
| uconfig.h | User-configurable settings |
| ucpmap.h | C API: This file defines an abstract map from Unicode code points to integer values |
| ucptrie.h | C API: This file defines an immutable Unicode code point trie |
| ucurr.h | C API: Encapsulates information about a currency |
| udata.h | C API: Data loading interface |
| udisplaycontext.h | C API: Display context types (enum values) |
| uenum.h | C API: String Enumeration |
| uidna.h | C API: Internationalizing Domain Names in Applications (IDNA) |
| uiter.h | C API: Unicode Character Iteration |
| uldnames.h | C API: Provides display names of Locale ids and their components |
| uloc.h | C API: Locale ID functionality similar to C++ class Locale |
| ulocale.h | C API: Locale ID functionality similar to C++ class Locale |
| ulocbuilder.h | C API: Builder API for Locale |
| umachine.h | Basic types and constants for UTF |
| umisc.h | C API: Miscellaneous definitions |
| umutablecptrie.h | C API: This file defines a mutable Unicode code point trie |
| unifilt.h | C++ API: Unicode Filter |
| unifunct.h | C++ API: Unicode Functor |
| unimatch.h | C++ API: Unicode Matcher |
| uniset.h | C++ API: Unicode Set |
| unistr.h | C++ API: Unicode String |
| unorm.h | C API: Unicode Normalization |
| unorm2.h | C API: New API for Unicode Normalization |
| uobject.h | C++ API: Common ICU base class UObject |
| urep.h | C API: Callbacks for UReplaceable |
| ures.h | C API: Resource Bundle |
| uscript.h | C API: Unicode Script Information |
| uset.h | C API: Unicode Set |
| usetiter.h | C++ API: UnicodeSetIterator iterates over the contents of a UnicodeSet |
| ushape.h | C API: Arabic shaping |
| usprep.h | C API: Implements the StringPrep algorithm |
| ustring.h | C API: Unicode string handling functions |
| ustringtrie.h | C API: Helper definitions for dictionary trie APIs |
| utext.h | C API: Abstract Unicode Text API |
| utf.h | C API: Code point macros |
| utf16.h | C API: 16-bit Unicode handling macros |
| utf32.h | C API: UTF-32 macros |
| utf8.h | C API: 8-bit Unicode handling macros |
| utf_old.h | C API: Deprecated macros for Unicode string handling |
| utrace.h | C API: Definitions for ICU tracing/logging |
| utypes.h | Basic definitions for ICU, for both C and C++ APIs |
| uvernum.h | C API: definitions of ICU version numbers |
 uversion.h | C API: API for accessing ICU version numbers |
| i18n | |
| unicode | |
| alphaindex.h | C++ API: Index Characters |
| basictz.h | C++ API: ICU TimeZone base class |
| calendar.h | C++ API: Calendar object |
| choicfmt.h | C++ API: Choice Format |
| coleitr.h | C++ API: Collation Element Iterator |
| coll.h | C++ API: Collation Service |
| compactdecimalformat.h | C++ API: Compatibility APIs for compact decimal number formatting |
| curramt.h | C++ API: Currency Amount Object |
| currpinf.h | C++ API: Currency Plural Information used by Decimal Format |
| currunit.h | C++ API: Currency Unit Information |
| datefmt.h | C++ API: Abstract class for converting dates |
| dcfmtsym.h | C++ API: Symbols for formatting numbers |
| decimfmt.h | C++ API: Compatibility APIs for decimal formatting |
| displayoptions.h | C++ API: Display options class |
| dtfmtsym.h | C++ API: Symbols for formatting dates |
| dtitvfmt.h | C++ API: Format and parse date interval in a language-independent manner |
| dtitvinf.h | C++ API: Date/Time interval patterns for formatting date/time interval |
| dtptngen.h | C++ API: Date/Time Pattern Generator |
| dtrule.h | C++ API: Rule for specifying date and time in an year |
| fieldpos.h | C++ API: FieldPosition identifies the fields in a formatted output |
| fmtable.h | C++ API: Formattable is a thin wrapper for primitive types used for formatting and parsing |
| format.h | C++ API: Base class for all formats |
| formattednumber.h | C API: Formatted number result from various number formatting functions |
| formattedvalue.h | C++ API: Abstract operations for localized strings |
| fpositer.h | C++ API: FieldPosition Iterator |
| gender.h | C++ API: GenderInfo computes the gender of a list |
| gregocal.h | C++ API: Concrete class which provides the standard calendar |
| listformatter.h | C++ API: API for formatting a list |
| measfmt.h | C++ API: Compatibility APIs for measure formatting |
| measunit.h | C++ API: A unit for measuring a quantity |
| measure.h | C++ API: MeasureUnit object |
| messageformat2.h | C++ API: Formats messages using the draft MessageFormat 2.0 |
| messageformat2_arguments.h | C++ API: Formats messages using the draft MessageFormat 2.0 |
| messageformat2_data_model.h | |
| messageformat2_data_model_names.h | |
| messageformat2_formattable.h | |
| messageformat2_function_registry.h | |
| msgfmt.h | C++ API: Formats messages in a language-neutral way |
| nounit.h | C++ API: units for percent and permille |
| numberformatter.h | C++ API: All-in-one formatter for localized numbers, currencies, and units |
| numberrangeformatter.h | C++ API: Library for localized formatting of number, currency, and unit ranges |
| numfmt.h | C++ API: Compatibility APIs for number formatting |
| numsys.h | C++ API: NumberingSystem object |
| plurfmt.h | C++ API: PluralFormat object |
| plurrule.h | C++ API: PluralRules object |
| rbnf.h | C++ API: Rule Based Number Format |
| rbtz.h | C++ API: Rule based customizable time zone |
| regex.h | C++ API: Regular Expressions |
| region.h | C++ API: Region classes (territory containment) |
| reldatefmt.h | C++ API: Formats relative dates such as "1 day ago" or "tomorrow" |
| scientificnumberformatter.h | C++ API: Formats in scientific notation |
| search.h | C++ API: SearchIterator object |
| selfmt.h | C++ API: SelectFormat object |
| simplenumberformatter.h | C++ API: Simple number formatting focused on low memory and code size |
| simpletz.h | C++ API: SimpleTimeZone is a concrete subclass of TimeZone |
| smpdtfmt.h | C++ API: Format and parse dates in a language-independent manner |
| sortkey.h | C++ API: Keys for comparing strings multiple times |
| stsearch.h | C++ API: Service for searching text based on RuleBasedCollator |
| tblcoll.h | C++ API: The RuleBasedCollator class implements the Collator abstract base class |
| timezone.h | C++ API: TimeZone object |
| tmunit.h | C++ API: time unit object |
| tmutamt.h | C++ API: time unit amount object |
| tmutfmt.h | C++ API: Format and parse duration in single time unit |
| translit.h | C++ API: Transforms text from one format to another |
| tzfmt.h | C++ API: TimeZoneFormat |
| tznames.h | C++ API: TimeZoneNames |
| tzrule.h | C++ API: Time zone rule classes |
| tztrans.h | C++ API: Time zone transition |
| ucal.h | C API: Calendar |
| ucol.h | C API: Collator |
| ucoleitr.h | C API: UCollationElements |
| ucsdet.h | C API: Charset Detection API |
| udat.h | C API: DateFormat |
| udateintervalformat.h | C API: Format a date interval |
| udatpg.h | C API: Wrapper for icu::DateTimePatternGenerator (unicode/dtptngen.h) |
| udisplayoptions.h | C API: Display options (enum types, values, helper functions) |
| ufieldpositer.h | C API: UFieldPositionIterator for use with format APIs |
| uformattable.h | C API: UFormattable is a thin wrapper for primitive types used for formatting and parsing |
| uformattednumber.h | C API: Formatted number result from various number formatting functions |
| uformattedvalue.h | C API: Abstract operations for localized strings |
| ugender.h | C API: The purpose of this API is to compute the gender of a list as a whole given the gender of each element |
| ulistformatter.h | C API: Format a list in a locale-appropriate way |
| ulocdata.h | C API: Provides access to locale data |
| umsg.h | C API: MessageFormat |
| unirepl.h | C++ API: UnicodeReplacer |
| unum.h | C API: Compatibility APIs for number formatting |
| unumberformatter.h | C API: Localized number formatting; not recommended for C++ |
| unumberoptions.h | C API: Header-only input options for various number formatting APIs |
| unumberrangeformatter.h | C API: Localized number range formatting |
| unumsys.h | C API: UNumberingSystem, information about numbering systems |
| upluralrules.h | C API: Plural rules, select plural keywords for numeric values |
| uregex.h | C API: Regular Expressions |
| uregion.h | C API: URegion (territory containment and mapping) |
| ureldatefmt.h | C API: URelativeDateTimeFormatter, relative date formatting of unit + numeric offset |
| usearch.h | C API: StringSearch |
| usimplenumberformatter.h | C API: Simple number formatting focused on low memory and code size |
| uspoof.h | C API: Unicode Security and Spoofing Detection |
| utmscale.h | C API: Universal Time Scale |
| utrans.h | C API: Transliterator |
| vtzone.h | C++ API: RFC2445 VTIMEZONE support |
| io | |
| unicode | |
| ustdio.h | C API: Unicode stdio-like API |
| ustream.h | C++ API: Unicode iostream like API |
 layoutex | |
| layout | |
| ParagraphLayout.h | C++ API: Paragraph Layout |
| playout.h | C API for paragraph layout |
| plruns.h | C API for run arrays |
| RunArrays.h | C++ API: base class for building classes which represent data that is associated with runs of text |
