What does the "O/A" in the company name stand for?

The "O/A" stands for "Operating As".

Being a small operator of a "one man" handyman business I have found that I do not bring in sufficient revenue to afford the many options and reponsibilities of incorporating my business so I do what I can and I operate my handyman general contracting business as a sole proprietor under the trade name, "Handyman Reality", and with a business insurance umbrella package.