In 1996, Caldera, Inc. accused Microsoft of several anti-competitive practices, including issuing vaporware announcements, creating FUD, and excluding competitors from participating in beta-test programs in order to destroy competition in the DOS market.[10][11] One of the claims was related to having modified Windows 3.1 so that it would not run on DR DOS 6.0 although there were no technical reasons for it not to work.[10][12] This was caused by the so called AARD code, some encrypted piece of code, which had been found in a number of Microsoft programs. The code would fake nonsensical error messages if run on DR DOS, like:[13][14]