BIP‑353: Clarify TXT record structure and concatenation order (single RR; RDATA order; no cross‑RR joins)

Clarifies existing intent without changing the on‑wire format. • Publishers: one TXT RR whose RDATA may contain multiple <character-string>s (≤255 bytes each, RFC 1035 §3.3.14). • Clients: concatenate the RR’s strings in RDATA order (no separators) before parsing; do not concatenate across multiple TXT RRs; if multiple bitcoin: TXT RRs exist at the same name, treat as invalid.

Specification