Last year, I paid a professional tax preparer to file the tax return for my small business, and he added a couple of extra pages (that he entitled "Additional Information from 2015 Tax Return) to my tax return where he itemized my Schedule C "Gross Receipts" (Line 1) as well as various Schedule C Part II Expenses like "Advertising" (Line 8), "Taxes & Licenses" (Line 23), etc. I assume this is not mandatory, since I couldn't find IRS instructions that say to do this, but is it a good idea to itemize expenses on a separate sheet of paper so the IRS can see exactly what my Office Expenses or Advertising expenses consisted of? I was thinking it might help answer questions that could trigger an audit. Of course the opposite could also happen if some of the itemized expenses raise questions that might not have otherwise existed.

How common is it for sole proprietors to itemize their Schedule C Part II Expenses on a separate sheet of paper, and is it a good idea to do this?

Thanks for your help.