Duke Nukem 3D Capture the Flag v1.2 is for version 1.3. It has 12 levels and the file is 1.5MB in size. The file name is dukectf12.zip. It was released on March 18, 1999.

Duke Nukem 3D Capture the Flag is as it's title implies a Dukematch capture the flag type TC. I only tested it to make sure it would load and run before listing it here.