In The Unicode Standard, Hangul implementation is discussed in  Chapter 18 East Asia.

Hangul was first encoded in The Unicode Standard version 1.1. The script is now encoded in the following blocks:

BlocksCharacter RangeAdded in Unicode VersionDocumentation
Hangul Jamo 1100..11FF 1.1  U1100.pdf
CJK Symbols and Punctuation 302E..302F 1.1  U3000.pdf
Hangul Compatibility Jamo 3130..318F 1.1  U3130.pdf
Enclosed CJK Letters and Months 3200..32FF 1.1  U3200.pdf
Hangul Jamo Extended-A A960..A97F 5.2  UA960.pdf
Hangul Syllables AC00..D7A3 2.0  UAC00.pdf
Hangul Jamo Extended-B D7B0..D7FF 5.2  UD7B0.pdf
Halfwidth and Fullwidth Forms FFA0..FFBE, FFC2..FFC7, FFCA..FFCF, FFD2..FFD7, FFDA..FFDC 1.1  UFF00.pdf

Subsequent to version 1.1, the following characters have been added to the Hangul blocks:

CharactersUnicode VersionDocumentation
115A..115E 5.2  n3168.pdf L2/07-076 and  n3242.pdf L2/07-103
11A3..11A7 5.2  n3168.pdf L2/07-076 and  n3242.pdf L2/07-103
11FA..11FF 5.2  n3168.pdf L2/07-076 and  n3242.pdf L2/07-103
321D..321E 4.0  n2392.pdf L2/01-388
327C..327D 4.0  n2392.pdf L2/01-388
327E 4.1  n2815.doc L2/04-267
A960..A97C 5.2  n3168.pdf L2/07-076 and  n3242.pdf L2/07-103
D7B0..D7C6 5.2  n3168.pdf L2/07-076 and  n3242.pdf L2/07-103
D7CB..D7FB 5.2  n3168.pdf L2/07-076 and  n3242.pdf L2/07-103

Documentation refers to  ISO Working Group and Unicode proposals

A number of proposals for its inclusion were submitted to the Unicode Technical Committee and WG2:

1993-10-28 Adding two Bangjeom characters (old Hangul tone marks) to UCS-2 — Kyongsok Kim ( WG2 N935, L2/97-015 (not online))

1993-10-29 A draft proposal on adding Gugyeol characters to UCS-2 — Kyongsok Kim (WG2 N936 (not online), L2/97-016 (not online))

1997-05-27 Report on JTC1 letter ballot on DAM No. 5 to ISO/IEC 10646-1 (Hangul) — B. Paterson (WG2 N1561 (not online), L2/97-125 (not online))

1997-06-30 Proposal Summary form for two Bangjeom characters (Old Hangul tone marks) — Korea (WG2 N1599 (not online), L2/97-149 (not online))

1997-06-30 Korean proposal on Gugyeol, reference N 936 — Korea (WG2 N1606 (not online), L2/97-151 (not online))

1998-12-08 Hangul syllable name rules, proposed for ISO/IEC 10646 2nd edition — Bruce Paterson ( WG2 N1942.doc,  L2/99-022)

1999-07-29 Proposal for a "more reasonable Korean Coded Character Set" KPS 9566-97 and GP 12052-89 — DPRK ( WG2 N2056,  L2/99-353)

1999-12-07 New Work item proposal (NP) for an amendment of the Korean part of ISO/IEC 10646-1:1993 — Democratic Peoples Republic of Korea ( L2/99-380)

1999-12-07 DPRK NP - JTC1 5999 p 1-5, originally submitted as WG2 N2056 (for full document see L2/99-380) — DPRK ( WG2 N2182,  L2/00-084)

2000-02-03 Expert contribution on the placement of additional unified ideographs from JIS X0213, HK, and Korea — V.S. Umamaheswaran, Murray Sargent ( L2/00-036)

2000-02-10 Technical justification of the proposal to amend the Korean character part of ISO/IEC 10646-1 and proposed addition of 79 symbolic characters — D.P.R. of Korea ( WG2 N2170.doc,  L2/00-066)

2000-03-02 Comments on DPRK New Work Item proposal on Korean characters — Kent Karlsson ( WG2 N2167.doc,  L2/00-073)

2000-03-19 South Korea's comments on N2056 (L2/00-084) — G. Gim, K. Kim ( WG2 N2193.doc,  L2/00-095)

2000-07-05 Letter from DPRK on ISO 10646 — DPRK ( L2/00-229)

2000-08-10 Proposal for the addition of 14 Korean Alphabets to 10646-1 — DPRK Korea ( WG2 N2243,  L2/00-284)

2000-08-10 Proposal to change existing name of Korean characters in 10646-1 — DPRK Korea ( WG2 N2245,  L2/00-286)

2000-08-10 Evidence for arrangement of Korean characters proposed by CSK — DPRK Korea ( WG2 N2246,  L2/00-287)

2000-08-30 (SC2.584) Comments to Korean proposals (L2/00-284 - 289) — Michael Everson ( L2/00-291)

2000-09-13 ROK's Comments about DPRK's proposals (WG2 N2231, 2243-2247) — Kyongsok KIM ( WG2 N2269.doc,  L2/00-333)

2001-02-24 A Report of Korean Script ad-hoc group — Korean ad-hoc ( WG2 N2331,  L2/01-128)

2001-09-03 Proposal to add the Hanja code tables of D P R of Korea into ISO/IEC 10646-1:2000(18194 ideographs to CJK Unified Ideographs and its Extension A) (includes Mapping table in plain text format) — DPRK ( WG2 N2376.doc,  L2/01-352 (same document as L2/01-351, separate cover and table)

2001-10-13 ROK’s comments about DPRK’s proposal to add 70 symbols to ISO/IEC 10646-1:2000 — Kyongsok KIM ( WG2 N2390,  L2/01-387)

2001-10-16 A Report of Korean Script ad hoc group meeting on Oct. 15, 2001 — Kyongsok Kim ( WG2 N2392,  L2/01-388)

2001-10-30 New ordering rules for Hangul, including rules for historic characters, and a DPRK delta — Kent Karlsson ( L2/01-402 See L2/01-469)

2001-11-16 Request to Korean ad hoc group to generate mapping tables between ROK and DPRK national standards from US NB and Unicode — V.S. Umamaheswaran ( WG2 N2407.doc,  L2/01-458)

2001-11-29 Ordering rules for Hangul — Kent Karlsson ( L2/01-469 repl. L2/01-402)

2002-02-23 Additional Hangul character decompositions for the proper support of Hangul — Kent Karlsson ( L2/02-109)

2002-04-30 New canonical decomposition & composition processes for Hangeul — Kyongsok Kim ( L2/02-236)

2002-05-22 Proposal to add the 122 compatibility Hanja code table of the D P R of Korea into the CJK Compatibility Ideographs of ISO/IEC 10646-1:2000 — Takayuki K.Sato,Tatsuo L. Kobayashi, Pak Tong Gi ( WG2 N2493.doc,  L2/02-232)

2002-06-10 Problems with the current CTT of ISO/IEC 14651 re Hangeul — Kyongsok Kim ( L2/02-242)

2002-06-10 New canonical decomposition & composition processes for Hangeul (better scan / modification of L2/02-236) — Kyongsok Kim ( L2/02-244)

2002-08-19 Hangeul related portion of CTT in ISO/IEC 14651 — Kyongsok Kim ( L2/02-308)

2003-02-11 Hangeul-related portion of CTT in ISO/IEC 14651 — Kyongsok Kim ( L2/03-054)

2003-02-11 Hangeul-related issues in UAX #15 — Kyongsok Kim ( L2/03-055)

2003-02-28 Hangul Collation Requirements — Mark Davis ( L2/03-081)

2003-03-04 Hangul Mapping Errors — Peter Edberg ( L2/03-100)

2003-06-21 Ordering Rules for Hangul — Kent Karlsson ( L2/03-221)

2003-07-11 Data table for Hangul Ordering (to accompany L2/03-221) — Kent Karlsson ( L2/03-222)

2004-03-09 Ordering rules for Hangul; CTT suggestion [WG2-N2715] — Kent Karlsson ( WG2 N2715.doc,  L2/04-108)

2004-10-21 Unicode 1 Hangul Mapping Errors — Andrew C West ( L2/04-392)

2005-01-25 Korean Transliteration Rules (Response to Action Item AI-43-11) — Kyongsok Kim ( WG2 N2918,  L2/05-032)

2005-09-14 Request to clarify text on conjoining Jamo — Asmus Freytag, Ken Whistler ( WG2 N2994.doc  L2/05-264)

2005-09-15 Clause 26.1 of ISO/IEC 10646:2003 — Korea N.B. ( WG2 N2996.doc,  L2/05-265)

2005-09-15 Clarification concerning Hangul syllable method — Michel Suignard ( WG2 N3006,  L2/05-269)

2005-12-05 Proposal to add the property Jamo_Short_Name property — Eric Muller ( L2/05-379)

2006-07-14 A new model for using Hangul Jamo — Korea N. B. ( WG2 N3113.doc,  L2/06-289)

2006-08-09 Hangul Jamo and Hangul precomposed syllable description — Kent Karlsson ( WG2 N3124,  L2/06-295)

2006-09-24 Auxiliary character decompositions for supporting Hangul (including data files) — Kent Karlsson ( L2/06-310)

2006-09-27 A Proposal to add new Hangul Jamo extended characters to BMP of UCS — Kim, Kyongsok, Dae Hyuk Ahn ( WG2 N3168,  L2/07-076)

2006-09-27 Add annotations for existing 5 Hangul Jamo names — KIM, Kyongsok; Dae Hyuk Ahn ( WG2 N3172,  L2/07-075)

2006-11-07 Sino-Korean number syllables — Kent Karlsson ( L2/06-383)

2007-04-16 Proposal for allocation of proposed Hangul Jamos in the BMP — Ireland N.B. ( WG2 N3242,  L2/07-103)

2007-04-17 A proposed method of preprocessing Hangul to be included as an Annex of ISO/IEC 14651 — Republic of Korea ( L2/07-112)

2007-04-22 Regarding ISO/IEC JTC 1/SC 2 N3925 — Kent Karlsson ( L2/07-122)

2007-04-23 A Proposal to add new Hangul Jamo extended characters to BMP of UCS — Kim, Kyongsok, Dae Hyuk Ahn ( WG2 N3257.doc,  L2/07-247)

2008-02-01 Proposal to add Nine Multi-Letter Jamo Characters — Kent Karlsson ( L2/08-084)

2008-05-02 An introduction of Korean Standard KS X 1026-1:2007, Hangul processing guide for information interchange — Korea NB / Kyongsok Kim ( WG2 N3422,  L2/08-225)

2008-10-14 A response to AI-52-8 — Korea NB / Kyongsok Kim ( WG2 N3535,  L2/08-375)

2009-02-26 Change Proposal for Informative Alias of U+3164 HANGUL FILLER — Ienup Sung ( L2/09-096)

2009-04-19 Clarification Regarding Use of Jamo Filler Characters: US / UTC Response to N3535, N3422 — USNB / UTC ( WG2 N3624,  L2/09-149)

2009-04-20 A response to AI-53-9-a and AI-53-9-b — Korea NB / Kyongsok Kim ( WG2 N3611,  L2/09-159)

2010-01-25 A solution proposed by R.O.Korea for incorrectly mapped compatibility chars — Korea N.B. ( WG2 N3747,  L2/10-087)

2010-09-20 R. O. Korea's Response to AI 55-2-a RE: K2 ~ K5 and M55.18 (Missing documents for Korean source references K2 to K5) — Korea N.B. ( WG2 N3898,  L2/10-366)

2011-10-20 Proposal to change the General_Category of Hangul tone marks U+302E and U+302F — Peter Constable, Laurențiu Iancu, Dwayne Robinson ( L2/11-402)

2015-03-20 kKorean vs. kHangul — Jaemin Chung ( L2/15-096)

2016-11-08 Proposal to add formal aliases to U+11EC through U+11EF — Jaemin Chung ( L2/16-363)

2017-04-27 Preliminary Proposal for Encoding New Hangul — S. and S. Oh ( L2/17-125)

2017-05-02 Comments on L2/17-125, "Preliminary Proposal for Encoding New Hangul characters (for some English consonant sounds)" — Jaemin Chung ( L2/17-126)

Recommendations to UTC #152 July-August 2017 on Script Proposals ( L2/17-255) (See point 20.)

UTC #152 Minutes ( L2/17-222) (See C.20 for decision and action items)

2017-07-24 Follow-up to L2/17-125 "Preliminary Proposal for Encoding New Hangul" and L2/17-126 "Comments on L2/17-125" — S. and S. Oh ( L2/17-241)

Recommendations to UTC #152 July-August 2017 on Script Proposals ( L2/17-255) (See point 20.)

UTC #152 Minutes ( L2/17-222) (See C.20 for decision and action items)