This presentation reports on the methodology and challenges of building digital dictionary data for the Hatoma-Japanese Dictionary, a comprehensive linguistic resource for the Hatoma language, one of the endangered languages spoken in the Yaeyama islands, Okinawa Prefecture, Japan. The dictionary consists of over 16,000 entries and provides thorough documentation of the language and culture of Hatoma Island. Recently, audio databases of its headwords and examples have been published online.

The Hatoma Yaeyaman language is classified as a South Ryukyuan language; all languages in this group are endangered, and proficient speakers are mostly confined to the elderly. Amidst emerging efforts to revitalize regional languages across the Yaeyama Islands, a digital dictionary featuring bilingual lookup, faceted search, and audio resources is essential for younger learners. To this end, we are compiling XML-encoded dictionary data based on TEI Lex-0. Developed by the EU-DARIAH Working Group on Lexical Resources, TEI Lex-0 is a forked schema of TEI that aims to provide a clearer and more unambiguous rule set for lexicographers.

Building upon the previous work of Nakagawa and Miyagawa (2023), we successfully translated most of the existing structures from the original book to the TEI Lex-0 framework. We encountered challenges in three primary areas and propose solutions for them:

• Cultural Content: The dictionary focuses on songs—a cultural pillar of the language—necessitating new ways to accommodate lyrics and metadata in the absence of specific elements for verses.

• Data Canonicalization: The original data contains unstructured definition texts with numerous free markups, which complicates the process of canonicalization for accurate structure detection.

• Schema Limitations: Currently, TEI Lex-0 does not support <media> or <ruby> elements. Furthermore, minor attribute values require further codification to allow for more precise descriptions within East Asian linguistic environments.