Since cannot be reduced further, it is called a "normal form".
One might call this mixed bag a form of cottage gardening.
He calls the progressive income tax a form of slavery.
It is not what you would call a "low-risk" form of transportation.
He is comfortable with calling his work a form of arranging.
Being subject to collateral consequences has been called a form of civil death.
You might call it a subtle form of political patronage.
You might call it a creative and aggressive form of marketing.
They recently decided to call rape a form of torture, which places it among the most serious war crimes.
This problem has grown to such an extent that it can be called a new form of slavery.