In The Unicode Standard, Bengali script implementation is discussed in  Chapter 12 South and Central Asia-I.

The Bengali script was first encoded in The Unicode Standard version 1.0. Since that time the encoding has undergone a small number of modifications; the script is encoded in the following block:

BlocksCharacter RangeAdded in Unicode VersionDocumentation
Bengali 0980..09FF 1.0  U0980.pdf

Vedic Extensions may be used with the Bengali script as well as many other Indic scripts.

Subsequent to version 1.0, the following characters have been added to the Bengali script:

CharactersUnicode VersionDocumentation
0980 7.0  WG2 N4157,  L2/11-359,  L2/12-121
09BD 4.0   n2425.pdf/ L2/02-117
09CE 4.1  n2809.pdf/ L2/04-264; supporting documents:  n2810.pdf/ L2/04-262,  n2811.pdf/ L2/04-192,  n2812.pdf/ L2/04-233,  n2813.pdf/ L2/04-252
09FB 5.2  n3311.pdf/ L2/07-192
09FC 10.0  L2/15-161
09FD 10.0  L2/15-172

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:

1995-05-01 Incorporation of Bengali Coded Character sets in the revision of ISO.IEC 10646-1 — Bangladesh S.T.I. (WG2 N1555 (not online), L2/97-120 (not online))

1997-06-29 Incorporation of Bangla (Bangladesh) coded character set in 10646 (L2/97-287 (not online))

1998-02-25 Draft Response to Bengali Proposal WG2 N1634 — Michael Everson (WG2 N1634 (not online), L2/98-058 (not online))

1998-03-18 Bengali encoding in ISO/IEC 10646 and BSD 1520 — Michael Everson ( WG2 N1714,   L2/02-108 (L2/98-091))

1998-04-16 Response to WG2 N1634, Incorporation of Bangla (Bengali) Coded Character Set in ISO/IEC 10646 — Aliprand ( L2/98-145)

2000-07-25 Bangladesh Standard: Specification for Bangla Coded for Information Interchange — Bangladesh ( WG2 N2261-2,  L2/00-305)

2000-08-23 Proposal Summary Form for character U+09BA, KHANDATA — Bangladesh ( WG2 N2261-1,  L2/00-304)

2000-08-23 Incorporation of Bangla (Bangladesh) coded character set in 10646 -1 — Bangladesh ( WG2 N2261,  L2/00-303)

2000-11-15 Unicode representation of Indian Scripts — M.N. Cooper ( L2/00-417)

2002-03-21 Additional Characters for Indic Scripts — Rick McGowan ( WG2 N2425,  L2/02-117)

2003-03-03 Proposed changes in the Unicode Standards for Indic Scripts - Bengali — Manoj Jain ( L2/03-084)

2003-03-03 Proposal for addition of BENGALI LETTER OPEN A & AND BENGALI LETTER CENTRAL E — Andy White ( L2/03-089)

2003-03-04 Sample Text for Bengali Sign Avagraha — Manoj Jain ( L2/03-104)

2003-03-05 Conjuncts: making sure we are right — Michael Everson ( L2/03-113)

2003-06-09 Formation of the Reph in Bengali Script — Paul Nelson ( L2/03-192)

2003-06-30 Bengali Script: Formation of the Reph and Yaphala, and use of the ZERO WIDTH JOINER and ZERO WIDTH NON-JOINER — Paul Nelson ( L2/03-209)

2003-08-18 Comment on Public Review Issue #9 Bengali Reph and Ya-Phalaa — Mike Meir ( L2/03-264)

2003-10-27 Comment on Public Review Issue 9 : Bengali Reph and Ya-Phalaa — Gautam Sengupta ( L2/03-388)

2003-10-29 Comments on Bengali Yaphala — Paul Nelson ( L2/03-394)

2004-02-01 Encoding Bangla Khanda-Ta With Ta+Virama — Gautam Sengupta ( L2/04-060)

2004-02-01 Encoding Bangla Khanda-Ta With Ta+Virama — Peter Constable ( L2/04-062)

2004-02-17 Encoding of Bengali Khanda Ta in Unicode (PRI #30 document) — Peter Constable ( WG2 N2810,  L2/04-262)

2004-03-09 Indic scripts collation grouping; CTT suggestion — Kent Karlsson ( WG2 2716.doc,  L2/04-109)

2004-06-07 FEEDBACK ON PR-30: Encoding of Bangla Khanda Ta in Unicode — Gautam Sengupta ( WG2 N2811,  L2/04-192)

2004-06-10 Letter to Mark Davis re Bengali Khanda Ta — Om Vikas ( WG2 N2812,  L2/04-233)

2004-06-15 Review of Bengali Khanda Ta and PRI-30 Feedback — Peter Constable ( WG2 N2813,  L2/04-252)

2004-06-17 Proposal to Encode Bengali Khanda Ta in the UCS — Peter Constable ( WG2 N2809,  L2/04-264)

2004-06-30 Proposal on Clarification and Consolidation of the Function of ZERO WIDTH JOINER in Indic Scripts — Peter Constable ( L2/04-279)

2004-08-04 Response to Public Review Issue #37 — Antoine Leca ( L2/04-328)

2004-08-06 Proposal for Assigning a Distinct Code Point to Bangla YA-phalaa — Gautam Sengupta ( L2/04-335)

2004-12-31 Indic collation: action items 99-20 and 99-29 — Cathy Wissink ( L2/04-432)

2005-01-13 Re: Gautam Sengupta's proposal for assigning a distinct code point to Bangla Yaphalaa — Mike Meir ( L2/05-005)

2005-01-29 Comments on PRI 59: Script Specific Danda and Double Danda — Eric Muller ( L2/05-055)

2005-02-07 Issues in Representation of Indic Scripts in Unicode (Unicode Conference Presentation) — Om Vikas ( L2/05-063)

2006-02-06 Use of ZWJ for Bengali CV “Ligatures” — Peter Constable ( L2/06-053)

2006-06-17 Comments on Indic Block Descriptions — Peter Constable ( L2/06-225)

2007-10-08 Proposal to Encode the Ganda Currency Mark for Bengali inISO/IEC 10646 — Anshuman Pandey ( WG2 N3311,  L2/07-192)

2008-03-02 Criteria for the encoding of script-specific dandas — Unicode and US National Body ( WG2 N3457,  L2/08-118)

2008-08-04 Public Review Issue #123: Bengali Currency Numerator Values — Ken Whistler ( L2/08-288)

2009-01-07 Bengali Issues — Bidyut Baran Chaudhuri ( L2/09-008)

2009-02-22 Prayer for proposing new character(s) for new scripts of Kamatapuri language — Kamatapuri Bhasha Unnayan Parishad ( L2/09-098)

2009-04-10 Comments on the Proposal to Encode Characters for the Kamatapuri Language (L2/09-098) — Anshuman Pandey ( L2/09-121)

2009-08-06 Proposals for discussion on Bengali Script in Unicode Meeting dated 10-14 August, 2009 — Bidyut Baran Chaudhuri ( L2/09-274)

2009-08-10 Unicode agenda for Bangla (Powerpoint presentation) — Bidyut Baran Chaudhuri ( L2/09-294)

2009-10-28 Proposal to add a Named UCS Sequence Identifier BENGALI LETTER KHINYA — UTC / Peter Constable ( WG2 N3729,  L2/09-383)

2010-01-25 Additions to Deva-Nagari Script & Bengali Script — Rabin Deka ( L2/10-029)

2010-01-27 Comments on Additions to Deva-Nagari Script & Bengali Script (L2/10-029) — Anshuman Pandey ( L2/10-050)

2010-01-29 Govt. of India’s inputs on document no. L2/10-029 — Swaran Lata ( L2/10-051)

2011-05-16 Bengali Om character — Barun Kumar Sahu ( L2/11-275)

2011-07-21 Letters regarding Assamese — A. Haque, S. Phukan ( L2/11-338)

2011-07-28 A clear policy on encoding OM characters — Shriramana Sharma ( L2/11-308)

2011-09-25 Assamese Writing System in the Unicode — Friends of Assam ( L2/11-350)

2011-10-21 Request to Add Annotations for Bengali ISSHAR to the Names List — Anshuman Pandey ( WG2 N4156,  L2/11-365)

2011-10-26 Article in Assamese — Rajen Barua ( L2/11-407)

2011-10-27 Letter from Swaran Lata, Gov't of India, re proposals — Swaran Lata ( L2/11-408)

2011-10-28 Revisions and Additional Annotations to the Names List for Bengali — Anshuman Pandey ( WG2 N4148,  L2/11-413)

2012-01-16 Status update on the hold on the Bengali block — Anshuman Pandey ( L2/12-062)

2012-02-07 Inputs of Govt. of India on various documents — Swaran Lata ( L2/12-079)

2012-04-23 Proposal to Encode the Sign ANJI for Bengali in ISO/IEC 10646 — Anshuman Pandey ( WG2 N4157,  L2/11-359,  L2/12-121)

2012-05-07 GOI Feedback on the various Indic related documents — Swaran Lata ( L2/12-184)

2012-07-26 GOI Feedback on the various Indic related document submitted to UTC — Swaran Lata ( L2/12-277)

2012-07-31 Indic Scripts in Unicode — Eric Muller ( L2/12-289)

2012-10-26 Two Technical problems Concerning Assamese — Jyotiprakash Tamuli ( L2/12-339)

2012-10-29 Proposal for minor, non-character, additions to UCS addressing concerns from Assamese — Martin Hosken ( L2/12-350)

2012-11-08 Adding Devanagri, Bengali and Myanmar digits to Script Extensions — Roozbeh Pournader ( L2/12-376)

2014-03-05 Proposal to include two Characters in the Bengali Block of UCS — Bangladesh ICT Division ( L2/14-083)

2014-12-13 Bengali Vowel Letter Aw (U+0985 U+09D7) Used in Kokborok — Sanghmitra Sahu ( L2/14-304)

2015-01-26 Feedback on proposal L2/14-304 to encode BENGALI LETTER AW — Shriramana Sharma ( L2/15-010)

2015-02-12 Bengali letter UA used in Kokborok — Sanghmitra Sahu ( L2/15-091)

2015-05-20 Script property of A8F1 COMBINING DEVANAGARI SIGN AVAGRAHA — Shriramana Sharma ( L2/15-162)

2015-07-09 Proposal to Encode an Abbreviation Sign for Bengali — Srinidhi A, Sridatta A ( L2/15-172)

2015-07-31 Proposal to encode 09FC BENGALI LETTER VEDIC ANUSVARA — Shriramana Sharma ( L2/15-161)

2015-07-31 Proposal to encode 1CF7 VEDIC SIGN ATIKRAMA — Shriramana Sharma ( L2/15-160)

2016-11-01 Proposal to encode the SANDHI MARK for Bengali — Srinidhi A, Sridatta A ( L2/16-322)

Recommendations to UTC #150 January 2017 on Script Proposals ( L2/17-037) (See point 4.)

UTC #150 Minutes ( L2/17-016) (See D.3.2 for decision and action items)

2017-04-17 Request for editorial updates to Indic scripts — Srinidhi A, Sridatta A ( L2/17-098)

Recommendations to UTC #152 July-August 2017 on Script Proposals ( L2/17-255) (See point 7.)

2017-04-19 Comments on L2/16-322 and L2/16-383, Sandhi marks for Bengali and Newa — Deborah Anderson ( L2/17-130)

Recommendations to UTC #151 May 2017 on Script Proposals ( L2/17-153) (See point 4.)

UTC #151 Minutes ( L2/17-103) (See D.3.3 for decision and action items)