Home / Glossary / SMP: Supplementary Multilingual Plane
March 19, 2024

SMP: Supplementary Multilingual Plane

March 19, 2024
Read 3 min

The Supplementary Multilingual Plane (SMP) is a character encoding plane used in Unicode to accommodate a vast range of characters beyond the Basic Multilingual Plane (BMP). Unicode is a standard for consistent encoding, representation, and handling of text in various writing systems. The SMP, also known as Plane 1, extends the Unicode character set beyond the initial 65,536 code points of the BMP, allowing for the representation of additional characters from diverse scripts, symbols, and special characters.


The Supplementary Multilingual Plane was introduced in Unicode version 2.0 to address the limitations of the BMP, which was originally thought to be sufficient for most commonly used scripts. As the need arose for encoding less common and historic scripts, technical symbols, and additional characters used in specialized domains, the SMP became necessary.

The SMP is divided into numbered blocks, each dedicated to specific scripts or character sets. These blocks are allocated to represent scripts like Arabic, Hebrew, Thai, Cyrillic, and numerous others, along with areas for mathematical symbols, music notation, and historical scripts. This organization allows for efficient searching, indexing, and processing of text that includes characters from the SMP.


The inclusion of the Supplementary Multilingual Plane in Unicode brings several advantages. Firstly, it allows for multilingual representation, accommodating a broader range of languages and writing systems. This is crucial in a globalized world, where communication, information exchange, and localization of software and content call for comprehensive character encoding.

Moreover, the SMP ensures compatibility with existing character sets and encodings, enabling the seamless interchange of text between diverse computing systems. It eliminates the need for ad hoc character mappings or transliteration schemes, promoting interoperability and reducing data loss or corruption in information exchange.

Additionally, the Supplementary Multilingual Plane offers support for specialized symbols and characters required in technical or domain-specific contexts. It caters to needs such as scientific notation, musical notation, historical scripts, and other niche applications, providing a standardized framework for encoding and processing such content.


The applications of the Supplementary Multilingual Plane are widespread, benefiting various fields within the realm of information technology. Localization and internationalization of software heavily rely on the SMP to accurately render text in different languages, scripts, and writing systems. It facilitates the seamless display of multilingual content, ensuring accurate representation and legibility for users across the globe.

Furthermore, domain-specific applications such as mathematical software, music notation software, and historical text analysis tools greatly benefit from the expanded character set offered by the SMP. These tools can now handle specialized symbols, characters, and notations with ease, providing comprehensive solutions for their respective domains.

In addition, the SMP plays a vital role in data interchange and communication protocols. From email communication to web technologies, the Supplementary Multilingual Plane ensures that text can be exchanged accurately and efficiently, regardless of the languages or scripts involved. This facilitates effective communication and collaboration in a globalized world.


The Supplementary Multilingual Plane’s inclusion in Unicode has revolutionized the representation and handling of text in information technology. With its extensive character set encompassing a wide range of languages, scripts, symbols, and specialized characters, the SMP enables the accurate encoding, rendering, and processing of multilingual content and domain-specific applications. Its adoption promotes interoperability, internationalization, and inclusive representation in the digital landscape, making it an indispensable component of modern information technology systems.

Recent Articles

Visit Blog

Cost to Develop an App Like Ally

How cloud call centers help Financial Firms?

Revolutionizing Fintech: Unleashing Success Through Seamless UX/UI Design

Back to top