Section 2 defines the circumstances in which the new duty will apply by reference to Schedule I to the Act. In broad terms, the duty will apply when a trustee is exercising powers of investment, acquisition of land, appointment of agents, nominees and custodians, and certain powers under the Trustee Act (Northern Ireland) 1958, such as the insurance of trust property. The duty of care will not apply where it is excluded or modified by the trust instrument. Subject to that, it can apply to the exercise of relevant powers conferred by this legislation, other statutory provisions, the trust instrument, court orders, or other sources.