Typically, you should use LPTSTR if you want that your application can be compiled to use wide-character strings in a UNICODE compilation, and narrow-character string otherwise.

Hence, you should normally use the "generic" form of all function calls, such as dxaStrDup instead of dxaStrDupA or dxaStrDupW. Similarly, you should use the _dt version of the function mappings, such as _dtprintf instead of _dnprintf or _dwprintf.

However, notice that you often cannot use LPTSTR or TCHAR for certain tasks, such as in communication protocol messages, if the protocol is specifically defined to use either LPSTR or LPWSTR (or CHAR or WCHAR). In such cases, you need to do an appropriate conditional conversion between your LPTSTR and the protocol's LPSTR or LPWSTR, and possibly also make a character set conversion.