Reports the protocol version actually negotiated. RFC 8996 deprecated TLS 1.0 and 1.1 in 2021; browsers now warn or refuse outright, and PCI DSS has prohibited them for card handling since 2018.
Impact is importance multiplied by the confidence tier’s weight — SPECIFICATION 1.0, RESEARCH 0.7, EMERGING 0.3, EXPERIMENTAL 0.1. Two rules backed by the same class of evidence therefore always carry the same weight, which is what makes the score reproducible rather than hand-tuned.