Are you sure, there are not 5 types of audits?
The TCMP (Taxpayer Compliance Measurement Program) is, or perhaps was, another type of very intrusive audit.
The mother of all audits is an audit conducted on a corporation or an individual because of their political position.
Actually the TCMP audit is the one designed to set the parameters of what is used to select future year returns for audit. It is how they set the formula for deductions which fall above or below a “normal” amount compared to total taxable income. It is what the prior writer numbered as 4.
The full cavity audit could be hidden in that group though if someone forced it into the “ramdom” selection process for TCMP audit. They are supposed to be machine generated.
There also used to be a group of audits conducted under the Federal Joint Strike Force Program. That program was eliminated some time ago with the disbanding of the Strike Forces designed to target organized crime.
This is the audit that I received. The guy spent months and even interviewed my neighbors about me.