(23)During the active red teaming in the testing phase, if necessary to allow for the continuation of the TLPT as a last resort in exceptional circumstances and once all alternative options have been exhausted, a collaborative testing activity that involves both the testers and the blue team, should be used. In the context of such limited purple teaming exercise, the following methods can be used: ‘catch-and-release’, where testers attempt to continue the scenarios, get detected and then resume the testing, ‘war gaming’, which allows for more complex scenarios to test strategic decision-making, or ‘collaborative proof-of-concept’ which enables testers and blue team members to jointly validate specific security measures, tools, or techniques in a controlled and cooperative environment.