Welcome to the home page for the MessageFormat Working Group, a subgroup of the Unicode CLDR-TC.

The Message Format Working Group (MFWG) is tasked with developing an industry standard for the representation of localizable message strings to be a successor to ICU MessageFormat. MFWG will recommend how to remove redundancies, make the syntax more usable, and support more complex features, such as gender, inflections, and speech. MFWG will also consider the integration of the new standard with programming environments, including, but not limited to, ICU, DOM, and ECMAScript, and with localization platform interchange. The output of MFWG will be a specification for the new syntax, which is expected to be on track to become a Unicode Technical Standard.

We are looking for participation from software developers, localization engineers and others with experience in Internationalization (I18N) and Localization (L10N). If you wish to contribute to this work, please review the information about the Contributor License Agreement.

To follow this work:

1. Apply to join our mailing list
2. Watch this repository (use the "Watch" button in the upper right corner)

To contribute to this work, in addition to the above:

1. Each individual MUST have a copy of the CLA on file.
2. Individuals who are employees of Unicode Member organizations SHOULD contact their member representative. Individuals who are not employees of Unicode Member organizations MUST contact the chair to request Invited Expert status. Employees of Unicode Member organizations MAY also apply for Invited Expert status, subject to approval from their member representative.

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This is the agenda document for upcoming calls of the MessageFormat Working Group of the CLDR-TC. We normally meet weekly on Mondays at 9:30 Pacific (America/Los_Angeles). This is currently UTC+7.

See here for your local time.

Information on joining calls is found in the calendar invite.

This block reserved for scribe rotation.

Recent scribes:

• 2025-07-14 TIM
• 2025-06-30 RGN
• 2025-06-23 MIH
• 2025-06-02 RGN
• 2025-05-12 TIM
• 2025-05-05 MIH <- it's getting embarrassing folks
• 2025-04-28 MIH <- let's give him a break
• 2025-04-21 MIH
• 2025-04-07 USA
• 2025-03-31 MIH
• 2025-03-24 TIM
• 2025-03-17 MIH
• 2025-03-10 USA
• 2025-02-24 MIH, TIM
• 2025-02-17 RGN
• 2025-02-10 MED, MRR
• 2025-02-03 MIH
• 2025-01-28 MRR <- overachiever
• 2025-01-21 MRR
• 2025-01-13 ECH
• 2024-12-16 MIH
• 2024-12-09 RGN
• 2024-11-25 TIM
• 2024-11-18 ECH
• 2024-11-11 MIH
• 2024-11-03 ECH
• 2024-10-28 HGO
• 2024-10-21 APP

• 2025-07-21 Regular Teleconference https://docs.google.com/document/d/1ns_XYK9jaH2Yzozz2uzrsTI_7Y1RxAsaaztbMSKUfX4/edit

The next meeting will be 21 July 2025 and is a regular WG Teleconference call.

To request that the chair add an issue to the agenda, add the label Agenda+ To request that the chair add an agenda item, send email to the message-format-wg group email.

Timeboxed review of items ready for merge.

PR	Description	Recommendation
#1084	Fix contradiction in markup resolution	Discuss
#1083	Include :date, :datetime, and :time with minimal options	Discuss
#1078	Define time zone values and conversions	Discuss
#1077	Include :datetime, :date, and :time with style options only	Discuss
#1076	Make expErrors use an array (and only an array)	Discuss
#1068	Design document for percent formatting	Merge
#1067	Semantic skeletons design	Discuss

https://github.com/unicode-org/message-format-wg/issues

Currently we have 27 open (was 26 last time).

• 19 are tagged for 48
• 3 are tagged “Future”
• 10 are Preview-Feedback
• 1 is tagged Feedback
• 2 are resolve-candidate and proposed for close.
• 2 are Agenda+ and proposed for discussion (see below)
• 1 is PR-Needed and needs a pull request
• 0 are ballots

Issue	Description	Recommendation
#866	CLDR semantic datetime skeleton spec is nearly ready and MF2 should use it	Discuss
#978	Interoperability concerns and normative-optional features	Discuss

What is the status of our various design docs?

Doc	Description	Status
percent-format	Format percents	Proposed
semantic-skeletons	Addition of semantic skeletons to date/time formatting	Proposed
maintaining-registry	Maintaining the function registry	Needs Attention
number-selection	Define how selection on numbers happens	Needs Attention

Accepted, Obsolete, and Rejected Designs

Doc	Description	Status
dataflow-composability	Data Flow for Composable Functions	Obsolete
function-composition-part-1	Function Composition	Obsolete
beauty-contest	Choose between syntax options	Obsolete
selection-matching-options	Selection Matching Options (ballot)	Obsolete
syntax-exploration-2	Balloting of the revised syntax used in the Tech Preview	Obsolete
variants	A collection of message examples which require a branching logic to handle grammatical variations	Obsolete
formatted-parts	Define how format-to-parts works	Rejected
quoted-literals	Document the rationale for including quoted literals in MF and for choosing the | as the quote symbol	Accepted
builtin-registry-capabilities	Tech Preview default registry definition	Accepted
code-mode-introducer	Choose the pattern for complex messages	Accepted
data-driven-tests	Capture the planned approach for the test suite	Accepted
default-registry-and-mf1-compatibility	Default Registry and MF1 Compatibility	Accepted
delimiting-variant-patterns	Delimiting of Patterns in Complex Messages (Ballot)	Accepted
error-handling	Decide whether and what implementations do after a runtime error	Accepted
exact-match-selector-options	Choose the name for the “exact match” selector function (this is :string)	Accepted
expression-attributes	Define how attributes may be attached to expressions	Accepted
open-close-placeholders	Describe the use cases and requirements for placeholders that enclose parts of a pattern	Accepted
overriding-extending-namespacing	Defines how externally-authored functions can appear in a message; how externally authored options can appear; and effect of namespacing	Accepted
pattern-exterior-whitespace	Specify how whitespace inside of a pattern (at the start/end) works	Accepted
string-selection-formatting	Define how selection and formatting of string values takes place.	Accepted
variable-mutability	Describe how variables are named and how externally passed variables and internally defined variables interact	Accepted
bidi-usability	Manage bidi isolation	Accepted
selection-declaration	Effect of selectors on subsequent placeholders	Accepted