Most of the DDK files here are copyright 1992 and while some do say
The following IBM OS/2 source code is provided to you solely for
the purpose of assisting you in your development of OS/2 device
drivers. You may use this code in accordance with the IBM License
Agreement provided in the IBM Developer Connection Device Driver
Source Kit for OS/2. This Copyright statement may not be removed.
Which I take it is the copyright you reference. quite a few are
COPYRIGHT IBM CORPORATION, 1991, 1992
LICENSED MATERIAL - PROGRAM PROPERTY OF IBM
REFER TO COPYRIGHT INSTRUCTION FORM#G120-2083
RESTRICTED MATERIALS OF IBM
IBM CONFIDENTIAL
VERSION = V2.0
Some documentation has
COPYRIGHT LICENSE: This publication contains printed sample application programs in source language, which illustrate OS/2 programming techniques. You may copy, modify, and distribute these sample programs in any form without payment to IBM, for the purposes of developing, using, marketing or distributing application programs conforming to the OS/2 application programming interface.
Each copy of any portion of these sample programs or any derivative work, which is distributed to others, must include a copyright notice as follows: "(C) (your company name) (year). All rights reserved."
(C) Copyright International Business Machines Corporation 1996. All rights reserved.
Quickly Googling, I can't find the form.
Thinking about it, I did register as a developer at one time which may have been why I had access.