LjLjref

LjLjref is a lightweight reference notation and companion software ecosystem designed for digital libraries, scholarly databases, and linguistic corpora. It provides a compact, machine- and human-readable way to describe and resolve inter-item references, supporting nested structures, multilingual metadata, and versioned identifiers. The project emphasizes portability, offline operation, and interoperability with existing bibliographic standards.

The name LjLjref blends the stylized 'Lj' marker often used in multilingual text with 'ref' for reference, signaling its focus on cross-language linking. The concept emerged in the open-source digital humanities community in the early 2010s as a pragmatic alternative to heavier metadata schemas, with the first public specification released in 2015.

Core features include a simple textual syntax that encodes authors, titles, dates, and relational links, a resolver that can fetch and normalize referenced items, and validators that detect circular references or missing fields. LjLjref is designed to be language-agnostic and compatible with JSON-like metadata while retaining readable inline notation.

Applications span digital libraries, linguistic corpora, and scholarly repositories. By embedding LjLjref strings in metadata, researchers can reproduce linkage between cited works, datasets, and annotations across systems, enabling portable citations and reproducible research across multilingual contexts.

An example reference might appear as LjLjref:author=Doe;title=Linguistic Journal;year=2020;id=lj2020-04-01, which can be expanded by a resolver to retrieve full metadata. The format is still evolving, with ongoing discussions about schema extensions and cross-system compatibility.