The Language Metadata Table (LMT) is a controlled vocabulary of language codes developed specifically for the media and entertainment industry. Conceived by HBO in 2016 and maintained by the Content Delivery & Security Association (CDSA), LMT provides a standardized set of language identifiers built on IETF BCP 47 for use across content distribution, digital supply chain metadata, and media packaging workflows.
Background
LMT was created to address inconsistencies in how the entertainment industry identified languages across content distribution workflows. Before LMT, studios, distributors, and retailers used varying language codes and display names, causing confusion in areas such as subtitle identification, audio track labeling, and physical media packaging. HBO initiated the specification in 2016, and CDSA took on the role of hosting and maintaining the standard through a dedicated Working Group.
The LMT Working Group holds monthly meetings to vet definitions and language code values. As of version 5.0, released in April 2024, the Working Group has reached agreement on over 280 language codes with approximately 50 additional codes under active research. The table is published as a downloadable Excel file, with approved updates issued separately as PDF documents.
Purpose & Scope
LMT serves three core objectives as stated in its Working Group mission:
- Standardization -- creating a standardized table of language codes for implementation by entertainment and other industries, using IETF BCP 47 as the underlying framework
- Best practices -- facilitating efficient and consistent usage through documented guidelines
- Extension -- expanding code values through vetted field definitions and approved language codes, developed with a community of thought leaders from business, professional associations, and academic institutions
The standard addresses languages commonly encountered in global media distribution rather than attempting comprehensive linguistic coverage. Each LMT entry maps to a BCP 47 language tag derived from ISO 639, optionally extended with script, region, and variant subtags as defined by the IANA Language Subtag Registry.
Structure
Each LMT entry includes:
| Field | Description |
|---|---|
| LMT Code | The canonical language identifier |
| Language Name | English display name approved by the Working Group |
| BCP 47 Tag | Corresponding IETF language tag |
| Script | Writing system (where disambiguation is needed) |
| Region | Geographic qualifier (where applicable) |
The table distinguishes between language variants differing in script (e.g., Serbian in Latin vs. Cyrillic) or region (e.g., Brazilian Portuguese vs. European Portuguese), which is critical for media distribution where packaging and subtitle requirements differ by market.
Adoption & Compliance
According to the CDSA page, organizations are considered LMT-compliant simply by using the standard's codes. The benefits cited include enhanced interoperability, greater ease of use across internal departments and external vendors, reduced confusion, and lower overhead. LMT also accepts submissions for new language codes where a legitimate use case exists; proposed codes are reviewed and vetted by the Working Group.
Governance & Maintenance
LMT is maintained by the CDSA LMT Working Group, chaired by Yonah Levenson, Founder, Director, and Instructor of the Rutgers University Digital Asset Management Certificate program. The Working Group collaborates with leading fluent speakers in the global media and entertainment industry as well as the library and information science community. Updates are issued as new versions, with v5.0 being the current release as of April 2024.
Notable Implementations
LMT codes are used across several entertainment industry contexts:
- EMA (Entertainment Merchants Association) metadata standards reference LMT for language identification
- MovieLabs digital distribution metadata recommendations reference LMT
- Blu-ray Disc Association packaging specifications incorporate LMT language codes
- Major studios and distributors participating in the CDSA Working Group
Related Standards
- BCP 47 / RFC 5646 -- the IETF standard for language tags upon which LMT is based
- ISO 639 -- the international standard for language codes (parts 1, 2, and 3), providing the foundation for BCP 47 primary language subtags
- IANA Language Subtag Registry -- the authoritative registry of language subtags referenced by BCP 47