Type and Creator codes have been deprecated in Mac OS X which means that if they are not present the extension (suffix) of the file will determine which application is launched.

Files created programmatically through 4D may still have a type and creator code. The presence of this type and creator code takes precedence over the extension of the file and makes 4D the default application used when the file is double-clicked on.

To clear the type and creator codes you can use the following approach:

SET DOCUMENT CREATOR($filename;4*Char(0)) SET DOCUMENT TYPE($filename;4*Char(0))

Setting the type and creator codes in this manner will cause the Mac OS X operating system to rely on the extension of the file rather than the type and creator code.