If I may ...
JHFC! Semantics! Are you that dense? Maybe there should be FSBREAO? (For Sale By Real Estate Agent Owner) But how the f*ck would you pronounce that? If, a real estate agent, that owned their own house, wanted to sell their own house, outside the MLS system, and outside of their broker, that person can absolutely sell FSBO as an owner! But they must state that they are a Maryland licensed real estate salesperson in all advertising. Having to disclose they are a licensed agent is the only requirement. They are still the owner of the house. It is exactly the same absent the disclosure!
For sale by owner generally indicates that the seller is not a real estate professional. I believe most people would find it rather odd that a real estate agent would sell their own home outside of MLS and outside their brokerage but to each their own.