CDFs are a way to load C functions from DLLs into DfW and DG3. You can call any pascal exported function in a DLL with 0-10 parameters of types int, long, float, double and char buffer (string). You name the function the same as the name inside the DLL. This is also the name you can use to call them from inside DfW or a DQL in DG3. The function can also returnint, long, float, double and char buffer (string). When returning a string, you return the address of you char buffer in the DLL, so the DLL is the one managing the memory for the string. The default in modern compilers is to export the full name of the function, so you can see parameters, calling convention and return value. This is not supported by DfW, so you need to make sure you only export the actual function name C style and not the full name. You can read more of how to create your own in this document