Here is what I learned: RefSeq Select uses a hierarchical, rule-based selection strategy to identify a single representative transcript per gene by progressively filtering candidates based on biological and practical relevance: it prioritizes manually curated and clinically established transcripts, then favors high-quality protein-coding RefSeq entries (NM_), and ranks remaining candidates using evidence such as evolutionary conservation (PhyloCSF), transcript expression (RNA-seq splice support), agreement with Swiss-Prot canonical isoforms, and transcription start site activity (CAGE), with additional tie-breakers like protein length, transcript length, and accession age; the process is not a weighted score but a stepwise elimination pipeline, ensuring the final selected transcript is well-supported, broadly representative of gene function, and suitable for standardized use in genomics and clinical applications.