readQuoted treated \X as an escape for any X, so a single literal backslash in any quoted attribute value was silently dropped (data-path="C:\Users" parsed as C:Users) and a doubled backslash collapsed to one. Only the delimiter and the backslash itself are escapes now; every other backslash is a literal character. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>