In order to compare or search Unicode strings, software can use either composed or decomposed forms; this choice does not matter as long as it is the same for all strings involved in a search, comparison, etc. On the other hand, the choice of equivalence criteria can affect search results. For instance some typographic ligatures like U+FB03 (ﬃ), Roman numerals like U+2168 (Ⅸ) and even subscripts and superscripts, e.g. U+2075 (⁵) have their own Unicode code points. Canonical normalization (NF) does not affect any of these, but compatibility normalization (NFK) will decompose the ffi ligature into the constituent letters, so a search for U+0066 (f) as substring would succeed in an NFKC normalization of U+FB03 but not in NFC normalization of U+FB03. Likewise when searching for the Latin letter I (U+0049) in the precomposed Roman numeral Ⅸ (U+2168). Similarly the superscript "⁵" (U+2075) is transformed to "5" (U+0035) by compatibility mapping.