Non-discrimination principle: equal taxation treatment for nationals and enterprises across treaty states, subject to specified allowances. Article 23 implements a non-discrimination rule requiring that nationals and certain non-residents of one Contracting State not be subjected in the other State to taxation or related requirements that are different or more burdensome than those applied to local nationals. It exempts personal allowances based on civil status or family responsibilities from mandatory extension. It mandates comparable tax treatment for permanent establishments and similarly owned enterprises and provides that interest, royalties and fees for technical services paid to residents of the other State are deductible on the same conditions as payments to residents of the source State, subject to specified exceptions.