&reftitle.constants; &extension.constants;

`XDIFF_PATCH_NORMAL` (`integer`)

- This flag indicates that `xdiff_string_patch` and `xdiff_file_patch` functions should create result by applying patch to original content thus creating newer version of file. This is the default mode of operation.

`XDIFF_PATCH_REVERSE` (`integer`)

- This flag indicated that `xdiff_string_patch` and `xdiff_file_patch` functions should create result by reversing patch changed from newer content thus creating original version.