None of the acronyms I recognized.

You can keep learning here.Generally speaking there are 2 main types of loans for investors: “Conventional” and “Portfolio”Conventional - I'll define these as loans that come from Fannie Mae and Freddie Mac (if you recognize those names).

The bank recognizes that the REI (borrower) has no risk in property. 

We do the every day deals, month in and month out and whatever real estate niche you choose, recognizing that it is going to require a lot of push and effort to actually get where you want to be.

@George Wolff,  No, you do not have to reinvest the entire amount of your sale - if you're willing to incur some recognized taxable gain.  

But folks fail to recognize rents are also much higher.

This really limits any complaints from the lawyers about the contract - and from sellers who may recognize the form and/or think I am more professional because I am not using a one page contract to purchase a $100k+ asset of theirs.

So, in traditional, conventional lending, meaning Fannie Mae or Freddie Mac (if you recognize those names), a second home is one that you occupy for "part" of the year. 

I'm currently researching how to effectively navigate this appeal process.A bit more context:The property has a zoning permit dated 1/16/1956, which includes a variance recognizing it as a three-family unit.I do not possess a building permit that explicitly authorizes use as a three-family dwelling.I'm seeking advice tailored to the Philadelphia, PA area, particularly regarding this situation.

I recognize this is not quantifiable, however it is very apparent in the community.