During the credits of old films, I’ve noticed that some names are accompanied by the phrase nár. umĕlec or zasl. umĕlec. What do they mean?

These were communist-era titles bestowed on outstanding figures in the arts (in fact they were inaugurated by Masaryk). The higher honor is National Artist (Národní umĕlec) while the lesser one is Distinguished Artist (Zasloužilý umĕlec). Naturally, it wasn’t just artistic achievement but political criteria that were used in choosing recipients. Few artists had the courage to refuse the award which was accompanied by a higher salary and other perks. Among the holders of the titles were the poet Jaroslav Seifert, the actors Jan Werich and Vladimír Menšík, and the opera singer Peter Dvorský. The awarding of such titles is an indication of the high regard in which cutural figures are held.