Overwrite mode (initial)

The overwrite mode (initial) feature is not supported for DBCS input.
  1. When you type into a browser, the browser controls whether you can overwrite. Some browser implementations do not allow any overwriting, while others allow overwriting only for SBCS.
  2. One DBCS character is inserted before any SBCS or DBCS character regardless of whether overwrite mode is enabled.
  3. An SBCS character can overwrite one DBCS character, including SO/SI characters.