Non-controlling interests (NCI) represent the equity in a subsidiary not attributable, directly or indirectly, to a parent. Under IFRS 10, NCI must be presented within equity in the consolidated statement of financial position — clearly separated from the equity of the parent's owners. This is not optional: IFRS 10.22 is explicit that NCI belongs inside equity, never as a liability or mezzanine item. The standard also governs how profit or loss and other comprehensive income are allocated between the parent and NCI, regardless of whether that allocation produces a deficit balance for NCI.