Employment Law Questions? Ask an Employment Lawyer.
Thank you for the information and your question. Having worked with security clearance issues before I can tell you that it is better to err on the side of caution and disclose rather than not to. In this case if you were told that you would not be renewed because of unsatisfactory performance and you then resigned, that would fall under number 4 on the list. That is not going to keep you from passing a security clearance check and, at most, you will just need to explain the circumstances of your resignation. If you do not disclose this, and they speak to your former employer about why you left, they may have more questions about why you didn't disclose the circumstances.
Please feel free to ask follow up questions if you have them.