In short
A power of attorney is the official document by which one person transfers the authority to act on their behalf to another. For transactions such as a title transfer it must be drawn up before a notary and the authority stated explicitly.
In a power of attorney given for a property transaction the scope of authority is set out line by line: which property, which transaction, sale or mortgage, whether there is a price limit. A document written in general terms causes problems at the land registry and weakens the protection of the person granting it.
A buyer or seller abroad can have the document drawn up at a Turkish consulate in their country of residence. Documents prepared outside a consulate require an apostille and a sworn translation. Including a photograph and stating explicitly that it will be used in land registry transactions prevents most of the delays that occur on the day.
Why it matters to an investor
For an investor living abroad a power of attorney is the only way to run the whole process without buying a plane ticket. But the same document can also make the authority unlimited. A properly drafted one makes the work easier while confining the authority to a single transaction.