Retirement tax questions

The term "rollover IRA" is an industry term not an IRS one ... it designates that it came from a 401K and if you have a new job with a 401K who allows the old 401K money to transfer in then you know which IRA you can move it from ... nothing more than that.  Once the money left the 401K and was put into an IRA then to the IRS it is just an IRA.