# Extended functionality

## Code reference processing

DITA-OT supports defining the code reference target file encoding using the `format` attribute. The supported format is:

    format (";" space* "charset=" charset)?

If charset is not defined system default charset will be used. If charset is not recognized or supported, DOTJ052E error is thrown and system default charset is used as a fall-back.

    <coderef href="unicode.txt" format="txt; charset=UTF-8"/>