Online certificates or letters are not legal.A more important issue: this is a "request for reasonable accommodation" and you don't have to accept it if the request is unreasonable.

And a city certification along with a rental license should be requested as a proof of current use.

(a) If a sale in error under Section 21-310, 22-35, or 22-50 is declared, the amount refunded shall also include all costs paid by the owner of the certificate of purchase or his or her assignor which were posted to the tax judgment, sale, redemption and forfeiture record.

I am wondering if I should start looking into licenses or certificates...

Attend NYU continuing professional education, Baruch certification program, or Florida International University online programs to earn an Advanced Certificate in Real Estate

In the heart of central Pennsylvania I am overseeing a 60 unit, multi-family, town home flats project that sets the standard for energy efficient construction 70% higher than a LEED certification.  

Many of the flood homes in Houston will have high insurance rates if they are in the flood plain and don't have elevation certificates.

I work in property management on the management side and have a partner that has several years and certifications on the maintenance side and a team.

I'm considering using an VHDA FHA Plus loan and obtaining a VHDA Mortgage Credit Certificate to purchase my first owner occupied investment property.

In my experience, as part of your loan, you will be asked to fill out an occupancy certification affidavit, in which you will declare whether you intend to use the property as your primary residence for at least a year.