•c — Case

•c Y folds case. 1•c Y converts to upper case, and ¯1•c Y to lower case. A character vector converts as text, with Unicode’s full case mappings: ß becomes SS, and a Σ that ends a word lowercases to ς. Any other character converts on its own, and stays unchanged when its mapping has more than one character. Folding converts to upper case, then to lower case. •c keeps the argument’s nesting and leaves items that aren’t characters unchanged.

•c "AbC"           ⍝ "abc"
1•c "AbC"          ⍝ "ABC"
1•c "straße"       ⍝ "STRASSE"
¯1•c "ΟΔΟΣ"        ⍝ "οδος"