141.This section limits the circumstances in which a Revenue Scotland assessment can be made under section 98 or 99 to situations which arose because of careless or deliberate behaviour by the taxpayer, a person acting on behalf of the taxpayer or a person who was a partner of the taxpayer at the relevant time. It also prohibits a Revenue Scotland assessment being made under those provisions if the situation was attributable to a mistake in the calculation of the tax liability that was in accordance with generally prevailing practice at the time the return was made.