1099 tax form w/cash in lieu (CIL) trade under $20 is in Supplemental Section Not Reported to IRS. CIL sale doesn't show in 1099-B section. Should I report it to the IRS?

Yes, you should report it.  I would use "Various" as the acquisition date.  I always report cash i lieu transactions with a zero cost basis, but I know others that use the amount of cash of cash received, which results in no gain or loss.   

When entering those CIL transactions into the 1099-B what Sale Section should they be placed under? 

Below are the options that could possibly apply:

1. Long-term basis not reported to IRS (uncovered)
2. Long-term did not receive 1099-B form
3. Unknown term not reported to IRS

These CIL transactions were on my Schwab 1099 tax form in the supplemental section not reported to IRS. 

Thank you very much!