Specifications

Q: How can I find out whether a particular issue is covered by a specification published by the Consortium. And where do I look it up?

The Unicode Standard and related standards contain a number of specifications or guidelines for dealing with different programming tasks. Sometimes it's hard to find these as they are not all provided as specific, dedicated documents.

The following table lists subject areas for which the core specification of the Unicode Standard.

General
General Category, Default-Ignorable, plus those used in other specifications	Chapter 4
character properties (Unihan)	UAX #38
Unikemet)	UAX #57
Additional information for Cuneiform: references to additional data specific to the Sumero-Akkadian Cuneiform script	UTR #56
UCD	UAX #44
XML representation of the UCD	UAX #42
§ 4.2 Case.	§ 3.13
Characters with Unusual Properties: characters that implementers need to pay special attention to	§ 4.12
Script Property: usage model for determining text runs in a given script	UAX #24
Unicode Support of Mathematics: guidelines for mathematical usage	UTR #25
emoji characters	UTR #51
character sequences	UAX #34
Encodings
UTF-32 conversion and validation	§ 3.9
Unicode Encoding Schemes: UTF-8, UTF-16 (BE/LE), UTF-32 (BE/LE) conversion and validation	§ 3.10
Binary Order: UTF-8 order vs. UTF-16 order	§ 5.17
code pages	UTS #22
A Standard Compression Scheme for Unicode: how to compress Unicode to about the same size as legacy	UTS #6
EBCDIC systems	UTR #16
encoding scheme	UTR #26
ideographic variation sequences	§ 23.4
glyphs	UTS #37
Comparison (Collation)
canonical ordering	§ 3.11
§ 3.11 definitions	UAX #15
Unicode Collation Algorithm: the default mechanism for comparing, searching, matching, and ordering Unicode text	UTS #10
Parsing
Hangul Syllables: boundaries, parsing, (de/)composition, names	§ 3.12
Decimal Numbers: conversion and validation	§ 5.5
Unicode Regular Expression Guidelines: the features required in supporting regular expressions with Unicode	UTS #18
Unicode Identifiers and Syntax: how to parse identifiers	UAX #31
Unicode Source Code Handling: guidance for programming language designers on handling security issues in Unicode program text	UTS #55
§ 23.9 Tag Characters	§ 5.10
Variation Selectors: use, validation	§ 23.4
Ideographic Description Sequences: use, validation	§18.2
Segmentation
Newline Guidelines: how to handle newline characters	§ 5.8
Line Breaking Algorithm: the default way to determine where to linewrap	UAX #14
grapheme clusters, words, and sentences	UAX #29
Rendering
The Bidirectional Algorithm: required for display of Arabic and Hebrew text	UAX #9
Arabic Mark Rendering: sequence details for stable rendering of multiple marks	UAX #53
East Asian Width: the default determination of character width in East Asian contexts	UAX #11
Minimal shaping requirements for Tamil, and other complex scripts	Chapters 9-15
Vertical orientation adjustments for characters	UTR #50
Locale Data
internationalization	UTS #35
LDML data for hundreds of locales	CLDR
Identifiers and Security
Identifier and Syntax: security issues for identifiers	UAX #31
Unicode Security Considerations: guidelines for recognizing Unicode security problems and dealing with them	UTR #36
Unicode Security Mechanisms: useful tools for detecting spoofs	UTS #39
IDNA2003	UTS #46
Unicode Source Code Handling: guidance for programming language designers and programming environment developers to avoid security issues from improper handling of Unicode program text	UTS #55

Q: Which Unicode specifications are normative?

Some Unicode specifications are Unicode Standard, the material in Chapter 3, Unicode Technical Standards (About Unicode Technical Reports.

Q: Where can I find the rationale behind a given specification?

Specifications published by the encoded characters.

The following table list sources of information on specific technical decisions or the rationale behind them.

Unicode Technical Committee
Minutes and supporting documents	Register
Minutes and supporting documents	Search
Character Encoding
ScriptSource, information on scripts
Unicode Status for each script (Example: Arabic)
Wikipedia, information on Unicode blocks
History section for each Unicode block (Example: Arabic)
Emoji Proposals	By proposal
Emoji Proposals	By code point
Algorithms
Linebreaking Algorithm

Q: Where can I find out when a character was encoded or a feature was added to a given specification?

For both the Core Spec of the Unicode Standard and its Annexes, as well as Technical Standards and Reports, a "Modifications" section highlights changes from the preceding version. Tracking these backwards gives information on when a particular change was introduced, but the granularity is not particularly fine, nor is there a cross-reference with particular decisions and supporting documents. For DerivedAge.txt indicates the version a character was added to the standard. For some specifications an annotated version provides a more fine-grained documentation of the version and rationale for each change.