qbofile converts bank files between the formats accounting software uses. One of its output formats, QBO, declares its encoding in the file header: ENCODING:USASCII CHARSET:1252 So every payee name has to be reduced to printable ASCII before it goes in. The function that does it runs NFKD, strips the combining marks, applies a fallback map for the characters NFKD cannot decompose, and replaces whatever is still outside printable ASCII with a space: sanitizeText (...