Line B — Instruction 1040 (Schedule C)

Enter on line B the six-digit code from the Principal Business or Professional Activity Codes chart at the end of these

Any listed transaction that is the same as or substantially similar to tax avoidance transactions identified by the IRS in published guidance.
Any transaction offered to you or a related party under conditions of confidentiality for which you paid an advisor a fee of at least $50,000.
Certain transactions for which you or a related party have contractual protection against disallowance of the tax benefits.
Certain transactions resulting in a loss of at least $2 million in any single tax year or $4 million in any combination of tax years. (At least $50,000 for a single tax year if the loss arose from a foreign currency transaction defined in section 988(c)(1), whether or not the loss flows through from an S corporation or partnership.)

instructions. For nonstore retailers, select the PBA code by the primary product that your establishment sells. For example, establishments primarily selling prescription and nonprescription drugs select PBA code 456110 Pharmacies & drug retailers .