Software localization acronyms explained (l10n, i18n, TMS, MT & more)

If you are building multilingual software, you've probably seen terms like i18n, l10n, TMS, MT, or TM in documentation, GitHub issues, product discussions, or vendor comparisons.

But what do they actually mean, and how do they fit together?

This guide explains the most important software localization acronyms, with practical context for developers, SaaS teams, and product managers.

This glossary is especially useful if you:

• Implement internationalization in your codebase
• Manage localization for a SaaS product
• Compare translation management systems
• Work with translators or LSPs
• Plan international expansion

If you are new to localization strategy, this article complements our broader localization strategy guide for software & SaaS teams, which covers these topics in more depth.

Acronyms in software localization explained

Acronyms are shorter, abbreviated forms of words, usually created from the initial letters that are used in a given phrase. An example of an acronym is NATO (North Atlantic Treaty Organization) where the first letter of each word created a new abbreviated term.

We use acronyms to make it easier and faster to read certain words and terms. Instead of writing and reading a 4-word organization name, like the National Aeronautics and Space Administration, we simply write and pronounce it as NASA.

In a similar way, localization terminology can feel overwhelming because many terms are long, technical, and similar to each other.

For example:

• Internationalization
• Localization
• Multilingualization
• Globalization

To simplify communication, the industry uses shortened forms, often called numeronyms, where the number represents the count of letters between the first and last character.

That's how:

• localization becomes l10n
• internationalization becomes i18n
• globalization becomes g11n

Understanding these acronyms is essential when working with engineers, translation vendors, or localization platforms.

Key software localization acronyms

Below is a practical reference table of the most common localization acronyms used in SaaS and software development.

Below you'll find a detailed explanation of each term, with context for modern SaaS workflows.

l10n: Localization

l10n in an acronym for localization as there are 10 letters between "l" and "n".

Localization is the process of adapting software for a specific language or region.

It includes:

• Translating user interface text
• Adapting date, time, and currency formats
• Adjusting layout for text expansion
• Supporting cultural conventions
• Handling fonts and regional standards

Localization happens after proper internationalization is in place.

t9n: Translation

t9n is an acronym for translation. It is created in the same ways a l10n, by shortening the word by adding the number of characters inside.

Translation is the linguistic process of converting text from a source language into a target language while preserving meaning and intent.

Translation is one component of localization, but localization also includes cultural and technical adaptation beyond pure language conversion.

i18n: Internationalization

i18n is an acronym for internationalization. The acronym makes a long and complicated word easier to write.

What is internationalization? It is the process of designing and developing software so it can support multiple languages and regions without requiring major engineering changes later.

In practice, i18n includes:

• Separating text from code
• Using translation keys instead of hardcoded strings
• Supporting pluralization rules
• Formatting dates and currencies dynamically
• Handling Unicode properly
• Preparing layouts for text expansion
• Supporting RTL languages

Without proper i18n, localization becomes expensive, slow, and error-prone. Teams may need to rewrite UI components or adjust layouts every time they add a new language.

Dive deeper into what internationalization (i18n) means in software development and how to implement it effectively.

g11n: Globalization

g11n is an abbreviation of globalization. Globalization is a process in which a business starts to operate on an international scale.

The globalization process includes:

• Internationalization (i18n)
• Localization (l10n)
• Market research
• Pricing adaptation
• Legal compliance

xl8: Translate

xl8 is an abbreviation for translation, and it is used widely as a hashtag in social media. X is for "trans", then we add an l and 8 (ate).

While "xl8" is commonly used as shorthand for "translate," it's sometimes used informally when discussing translation tools and workflows. If you are comparing tools, see our guide to the best translation management systems for SaaS teams.

m17n: Multilingualization

m17n is an acronym of multilingualization. This term consists of adapting or localizing a website or app into multiple languages. Multilingualization can be done in many ways, including translation, localization, and internationalization.

ICU: International Components for Unicode

ICU is an acronym for International Components for Unicode. is a widely used library for handling internationalization features. In localization, ICU is often used for formatting:

• Plurals
• Dates
• Currencies
• Gender rules

Example:

{count, plural,
  one {# item}
  other {# items}
}

ICU message formatting is critical for correct plural handling across languages.

Learn more in our guide to ICU message format to understand how to use it effectively in your localization workflows.

TMS: Translation Management System

TMS is an acronym for Translation Management System. It is a software used to manage, automate, and organize the localization process across multiple languages.

A modern TMS typically includes translation memory, glossary management, workflow automation, API integrations, and quality assurance checks. It acts as the central hub connecting developers, translators, and product teams.

For SaaS companies, TMS platforms often integrate with Git repositories and CI/CD pipelines, enabling continuous localization and reducing manual export/import work.

Learn more in our translation management guide to understand how to choose and use a TMS effectively.

MT: Machine Translation

MT stands for Machine Translation. MT is the use of computer software to translate text from one language to another.

Modern MT systems use neural networks and large language models (LLMs) to improve fluency and context awareness. Popular examples include OpenAI-based systems, DeepL, Google Translate, and Microsoft Translator.

In software localization, MT is often combined with human review (MT + post-editing) to balance speed, cost, and quality. Many SaaS teams now use AI-assisted localization workflows that combine machine translation, translation memory, and automated QA checks.

TM: Translation Memory

TM is an acronym of Translation Memory. The term refers to a database that stores previously translated words, sentences, paragraphs or segments, for the future use by translators.

TM systems match new text against previously translated segments. Matches can be exact (100%) or partial (fuzzy matches), helping reduce cost and ensure consistency.

CAT: Computer-Aided Translation

CAT is an acronym of Computer-Aided Translation or machine-assisted translation. It is the use of computer software to assist a human translator in the translation process. There are a number of tools and features that the CAT systems offer to help translate various types of texts, like translation memory or built-in use of machine translation.

SL and TL: Source Language and Target Language

SL/TL are acronyms of Source Language and Target Language. Translators widely use these acronyms. Source language is the language that is to be translated to another language. Target language is the language that receives the translated text.

If you are planning localization beyond terminology, explore our guide to continuous localization or our software localization overview.

RTL and LTR: Right-to-Left and Left-to-Right languages

RTL and LTR are acronyms of Right-to-Left and Left-to-Right languages. They refer to the direction in which text is read and written.

• RTL languages include Arabic, Hebrew, Persian, and Urdu. They require special handling in UI design and development to ensure proper text alignment, cursor movement, and layout mirroring.
• LTR languages include English, Spanish, French, and most other languages. They are read and written from left to right.

LQA: Localization Quality Assurance

LQA refers to the process of reviewing translated content to ensure linguistic accuracy, consistency, and cultural appropriateness. It typically includes linguistic review, functional testing, and layout validation.

Learn more about localization quality assurance best practices to ensure your localized product meets high standards.

i18n vs l10n vs g11n: What's the difference?

Many people confuse internationalization (i18n), localization (l10n), and globalization (g11n).

• Internationalization (i18n): preparing software so it can support multiple languages
• Localization (l10n): adapting the product for a specific language or region
• Globalization (g11n): the overall business process of going global

In simple terms:

• i18n happens in engineering
• l10n happens in translation and content adaptation
• g11n happens at the business level

If you are planning this at scale, read our localization strategy guide for software & SaaS teams, which covers all these topics in detail.

Why understanding localization acronyms matters

Understanding these terms helps when:

• Planning your localization strategy
• Choosing a translation management system
• Working with translators or agencies
• Scaling to multiple markets

For SaaS companies, clarity around i18n, l10n, and translation workflows prevents costly architectural mistakes early on.

Before getting started with localization, check out our localization readiness checklist to make sure your product and team are prepared for the process.

Additional localization abbreviations you may encounter

Here are some additional abbreviations you may encounter in software localization:

• LSP: Language Service Provider. A company that provides translation and localization services.
• CMS: Content Management System. A software application used to create, manage, and modify digital content.
• API: Application Programming Interface. A set of rules that allows different software applications to communicate with each other.
• CLI: Command-Line Interface. A text-based interface used to interact with software applications.
• CI/CD: Continuous Integration / Continuous Deployment. A set of practices that enable developers to integrate code changes frequently and deploy them automatically.

FAQ about localization acronyms

If you are working on multilingual software, understanding these acronyms isn't just terminology, it's about understanding how your localization system works.