This is part of Win16 API which allow to create versions of program from one source code to run under OS/2 and Win16. Under OS/2 program can be running under Win-OS/2 if program is Windows NE executable, and with help on Windows Libraries for OS/2, if it is OS/2 NE executable. Here is a WLO to OS/2 API mapping draft

Win16 to OS/2 API mapping draft

Ordinal	Win16	OS/2
001	FATALEXIT
003	GETVERSION	No eq
004	LOCALINIT
005	LOCALALLOC
006	LOCALREALLOC
007	LOCALFREE
008	LOCALLOCK
009	LOCALUNLOCK
00a	LOCALSIZE
00b	LOCALHANDLE
00c	LOCALFLAGS
00d	LOCALCOMPACT
00e	LOCALNOTIFY
00f	GLOBALALLOC	DosAllocHuge
010	GLOBALREALLOC	DosReallocHuge
011	GLOBALFREE	DosFreeSeg
012	GLOBALLOCK	DosLockSeg
013	GLOBALUNLOCK	DosUnlockSeg
014	GLOBALSIZE	DosSizeSeg
015	GLOBALHANDLE
016	GLOBALFLAGS
017	LOCKSEGMENT
018	UNLOCKSEGMENT
019	GLOBALCOMPACT
01d	YIELD
01e	WAITEVENT
024	GETCURRENTTASK
025	GETCURRENTPDB
02d	LOADMODULE
02e	FREEMODULE
02f	GETMODULEHANDLE
030	GETMODULEUSAGE
031	GETMODULEFILENAME
032	GETPROCADDRESS
033	MAKEPROCINSTANCE
034	FREEPROCINSTANCE
036	GETINSTANCEDATA
037	CATCH
038	THROW
039	GETPROFILEINT
03a	GETPROFILESTRING
03b	WRITEPROFILESTRING
03c	FINDRESOURCE
03d	LOADRESOURCE
03e	LOCKRESOURCE
03f	FREERESOURCE
040	ACCESSRESOURCE
041	SIZEOFRESOURCE
042	ALLOCRESOURCE
043	SETRESOURCEHANDLER
044	INITATOMTABLE
045	FINDATOM
046	ADDATOM
047	DELETEATOM
048	GETATOMNAME
049	GETATOMHANDLE
04a	OPENFILE
04d	AnsiNext
04e	AnsiPrev
04f	AnsiUpper
050	AnsiLower
051	_LCLOSE
052	_LREAD
053	_LCREAT
054	_LLSEEK
055	_LOPEN
056	_LWRITE
057	lstrcmp
058	LSTRCPY
059	LSTRCAT
05a	LSTRLEN
05b	INITTASK
05c	GETTEMPDRIVE
05d	GETCODEHANDLE
05e	DEFINEHANDLETABLE
05f	LOADLIBRARY
060	FREELIBRARY
061	GETTEMPFILENAME
064	VALIDATECODESEGMENTS
066	DOS3CALL
067	NETBIOSCALL
068	GETCODEINFO
06a	SETSWAPAREASIZE
06b	SETERRORMODE
06c	SWITCHSTACKTO
06d	SWITCHSTACKBACK
06f	GLOBALWIRE
070	GLOBALUNWIRE
073	OUTPUTDEBUGSTRING
079	LOCALSHRINK
07f	GETPRIVATEPROFILEINT
080	GETPRIVATEPROFILESTRING
081	WRITEPRIVATEPROFILESTRING
082	FILECDR
083	GETDOSENVIRONMENT
084	GETWINFLAGS
086	GETWINDOWSDIRECTORY
087	GETSYSTEMDIRECTORY
088	GETDRIVETYPE
089	FATALAPPEXIT
08a	GETHEAPSPACES
096	DIRECTEDYIELD
098	GETNUMTASKS
09a	GLOBALNOTIFY
09c	LIMITEMSPAGES
0a3	GLOBALLRUOLDEST
0a4	GLOBALLRUNEWEST
0a6	WINEXEC
0a9	GETFREESPACE
0aa	ALLOCCSTODSALIAS
0ab	ALLOCDSTOCSALIAS
0af	ALLOCSELECTOR
0b0	FREESELECTOR
0b1	PRESTOCHANGOSELECTOR
0b8	GLOBALDOSALLOC
0b9	GLOBALDOSFREE
0ba	GETSELECTORBASE
0bb	SETSELECTORBASE
0bc	GETSELECTORLIMIT
0bd	SETSELECTORLIMIT
0bf	GLOBALPAGELOCK
0c0	GLOBALPAGEUNLOCK
0c4	SELECTORACCESSRIGHTS
0c5	GLOBALFIX
0c6	GLOBALUNFIX
0c7	SETHANDLECOUNT
0c8	VALIDATEFREESPACES
0cb	DEBUGBREAK
0cc	SWAPRECORDING
0ce	ALLOCSELECTORARRAY
0cf	ISDBCSLEADBYTE
136	LOCALHANDLEDELTA
140	ISTASK
143	ISROMMODULE
144	LOGERROR
145	LOGPARAMERROR
146	ISROMFILE
14e	ISBADREADPTR
14f	ISBADWRITEPTR
150	ISBADCODEPTR
151	ISBADSTRINGPTR
15b	ISBADHUGEWRITEPTR
15c	HMEMCPY
15d	_HREAD
15e	_HWRITE
161	LSTRCPYN
162	GETAPPCOMPATFLAGS
163	GETWINDEBUGINFO
164	SETWINDEBUGINFO