Under the new postal codes in Romania each locality is composed of 6-digit postal codes.

Thus, the first digit of postal code signifies the 10 postal regions of Romania, the two counties of the region, the third, the type locality, and the last three digits are assigned each locality in the county.
Some examples found here:

December 1, 1918 bl 510,207 Boulevard A1, M1-M6
December 1, 1918 av bl A2 510,007
Alba Alba Iulia Avenue December 1, 1918 bl A3 510,030
Alba Alba Iulia Avenue December 1, 1918 bl M10-M12 510,125
Alba Alba Iulia December 1, 1918 bl Avenue M7, M8, M9 510,008
Alba Alba Iulia Avenue December 1, 1918 no. 55-81, 38-T (case) 510,207
Alba Alba Iulia Avenue December 1, 1918 no. 83-T 510,214
Alba Alba Iulia Avenue Ferdinand I. No. 1-T 510,146
Alba Alba Iulia Avenue Ferdinand I. No. 2-70 510114
Alba Alba Iulia Avenue Ferdinand I. No. 72-T 510,164