Transliterates to lowercase ASCII Latin (so diacritics, ligatures, and full-width forms fold to a comparable base form), removes a leading "Retracted:" style marker, strips markup and punctuation, and collapses whitespace. The original title is retained elsewhere for reporting; this form is used solely for string distance. If the optional stringi package is installed, non-Latin scripts (such as CJK) are also romanized; otherwise they are dropped by the base fallback.