This Consensus Statement defines and discusses long non-coding RNAs (lncRNAs), their functions, challenges, and recommendations. LncRNAs are non-coding transcripts longer than 200 nucleotides, often derived from Pol II, and are involved in various biological processes, including chromatin modification, enhancer function, and phase separation of nuclear condensates. They are cell-type specific, regulate development and differentiation, and have roles in the cytoplasm, such as in translation and signaling. LncRNAs often have modular structures and are rich in repeats, which are increasingly recognized as important for their function. They are classified into three categories: small RNAs (less than 50 nt), Pol III transcripts, and lncRNAs (more than 500 nt). LncRNAs are often expressed from intergenic, antisense, or intronic regions and can be derived from pseudogenes. They are also involved in the regulation of gene expression, including through interactions with chromatin-modifying complexes and enhancers. LncRNAs are conserved in some cases but are generally less conserved than protein-coding sequences. Their expression is often cell-specific and can be influenced by environmental factors. LncRNAs have been shown to play important roles in various physiological and pathological processes, including cancer, developmental disorders, and stress responses. They are also involved in the formation of biomolecular condensates, which are essential for cellular organization and function. The study of lncRNAs is challenging due to their diverse functions and the difficulty in annotating them. However, advances in technology have enabled the identification and characterization of many lncRNAs, and there is a growing understanding of their roles in development, cell biology, and disease. The Consensus Statement recommends further research to better understand the functions of lncRNAs and their interactions with other cellular components.This Consensus Statement defines and discusses long non-coding RNAs (lncRNAs), their functions, challenges, and recommendations. LncRNAs are non-coding transcripts longer than 200 nucleotides, often derived from Pol II, and are involved in various biological processes, including chromatin modification, enhancer function, and phase separation of nuclear condensates. They are cell-type specific, regulate development and differentiation, and have roles in the cytoplasm, such as in translation and signaling. LncRNAs often have modular structures and are rich in repeats, which are increasingly recognized as important for their function. They are classified into three categories: small RNAs (less than 50 nt), Pol III transcripts, and lncRNAs (more than 500 nt). LncRNAs are often expressed from intergenic, antisense, or intronic regions and can be derived from pseudogenes. They are also involved in the regulation of gene expression, including through interactions with chromatin-modifying complexes and enhancers. LncRNAs are conserved in some cases but are generally less conserved than protein-coding sequences. Their expression is often cell-specific and can be influenced by environmental factors. LncRNAs have been shown to play important roles in various physiological and pathological processes, including cancer, developmental disorders, and stress responses. They are also involved in the formation of biomolecular condensates, which are essential for cellular organization and function. The study of lncRNAs is challenging due to their diverse functions and the difficulty in annotating them. However, advances in technology have enabled the identification and characterization of many lncRNAs, and there is a growing understanding of their roles in development, cell biology, and disease. The Consensus Statement recommends further research to better understand the functions of lncRNAs and their interactions with other cellular components.