Guidelines for the Naming of Circular RNAs.

Circular RNAs (circRNAs) have emerged as pivotal regulators in the posttranscriptional regulatory landscape, exhibiting unique properties such as increased stability and a range of biological functions due to their covalently closed-loop structure. Despite advancements in circRNA research, the field meets a significant challenge in the absence of a standardized nomenclature system, leading to confusion and hindering effective scientific communication. This chapter outlines the historical development, current state, and the necessity for a unified naming system in circRNA research. We highlight the role of databases in shaping circRNA nomenclature and discuss the implications of nomenclature ambiguity, especially with the identification of multiple circRNAs from single gene loci. We propose a systematic approach to naming circRNAs that incorporates the "circ" prefix, references to GENCODE/Ensembl transcripts, and annotations for unique structural features such as retained introns or alternative splicing. The adoption of such a nomenclature system is essential for enhancing clarity, ensuring reproducibility, and advancing our understanding of circRNA investigation.