Expanding conversions
An expanding conversion occurs when the length of the converted string is greater than that of the source string.
For example, an expanding conversion occurs when an ASCII mixed data string that contains DBCS characters is converted to EBCDIC mixed data. To prevent the loss of data on expanding conversions, use a varying-length string variable with a maximum length that is sufficient to contain the expansion.
Expanding conversions also can occur when string data is converted to or from Unicode. It can also occur between UTF-8 and UTF-16, depending on the data being converted. UTF-8 uses 1, 2, 3, or 4 bytes per character. UTF-16 uses 2 bytes per character, except for supplementary characters, which use two 2 byte code points for each character. If UTF-8 were being converted to UTF-16, a 1 byte character would be expanded to 2 bytes.