In addition to what he has said, in Philadelphia specifically, there is a Homestead exemption that can be applied for by resident owners.

If you don’t want to follow the federal housing law guidelines you’re not exempt from federal law.

Just to be safe, however, I have this text on the bottom of each page of my lease: "THIS TRANSACTION FALLS UNDER THE 2014 DODD FRANK LOAN RULES EXCLUSION 12CFR226.2 AND IS EXEMPT FROM PENALTIES" I also just had a colleague have a tenant/buyer actually exercise the option to purchase and used a FHA loan.

@Matt SmithHey Matt, be aware that the Tax Bill currently being floated in Washington is trying to do away with the 2 year requirement and make it 5 of 8 years instead of 2 of 5 years to qualify for the tax exemption.

AG cracks down on 133 O.C. loan modifiersAugust 12th, 2009, 11:31 am · 45 Comments · posted by Mathew Padilla(Clarification: Exemptions added.)Attorney General Jerry Brown today ordered California companies that promise to help people avoid foreclosure to immediately post $100,000 bonds and register with his office or face criminal prosecution.

Section 203.37a(c) lists the sales transactions exempt from this rule.

Originally posted by @Lisa Ryan:Philly also has an additional 2% transfer tax when you buy and when you sell real estate.The transfer tax in the City of Philadelphia is 4% total; although it is customary for that transfer tax to be split equally between buyer and seller in a sales transaction, you will find that the buyer will have to pay the full transfer tax on any HUD house for example (federal gov't is exempt from having to pay any transfer taxes so when the federal gov't is the seller the buyer pays it in full). 

I believe a Homestead can only be filed on a SFR, owner occupied (forever).Check if there's a Homeowners Tax Exemption (also OC)

If you do rely on them, be sure to read carefully through their exemptions and what they say about "degrees of fraud".This isn't legal advice, simply my opinion as an investor.

But to engage in license related activities you need a license.An exemption would be if you were an employee of a company retained to run an apartment building and the employees were under direct control and supervision of a broker.