The ten-year limitations period is not absolute. It can be extended if you voluntarily agree to do so. Back in the bad old dates (before 1998), the IRS used to put enormous pressure on taxpayers to agree to extend the limitations period beyond ten years--such extensions often lasted for ten or even twenty years.
Certified Ethical Hacker. Certified Ethical Hacker (CEH) is a qualification obtained by assessing the security of computer systems, using penetration testing techniques. The code for the CEH exam is 312-50, and the certification is in Version 9 as of 2016.
To become an HVAC technician, you need to complete a degree or certificate program or a formal apprenticeship. The time for completing certification varies, but it can be done in as little as six months.