An exclude list is a file that contains a list of tests in a test suite that should not be run for some reason. The list contains path names that uniquely identify tests to be excluded. When the JT Harness harness prepares to run a test, it checks to see if the test is on the exclude list, if it is, the test is ignored during the test run.

Exclude list files conventionally use the extension `.jtx` and may be supplied with a test suite or downloaded from a web site.