Particular embodiments of a computing device receive an indication of a character encoding system and a combining-character sequence. The character encoding system may comprise one or more ranges of character elements. The combining-character sequence may comprise two or more character elements. The two or more character elements may comprise at least one base letter and one or more combining marks. A mapping code may be determined for the combining-character sequence. If no mapping code exists, a next-available mapping code may be determined, and the combining-character sequence may be stored in association with the next-available mapping code in a data store on the computing device. A corresponding glyph may be determined based on the mapping code—if no glyph exists, the glyph may be generated or retrieved from a server and stored in association with the mapping code in the data store. Information may be provided to display the glyph.