DLS applications use most of the same header files as an OS/2 application. LAN Server also provides DLS-specific header files, DOSPRINT.H and NMPIPE.H, to support DLS application calls to remote print and named pipe functions. These files are stored by default in the \IBMLAN\NETSRC\H subdirectory.

For all the Print APIs, DLS applications should use the DOSPRINT.H header file instead of PMSPL.H. Also, you do not need to include the OS2.H header file or #define INCL_BASE. For example, use: 

 #include <dosprint.h>
for DLS applications instead of: 
 #define INCL_BASE
 #include <os2.h>
 #include <pmspl.h>
which is used only for 16-bit OS/2 applications.

Note: Simultaneous use of OS2DEF.H and WINDOWS.H header files produces conflicts resolved by constant and type redefinitions.