ISO 3166-2:RO is an ISO standard which defines geocodes: it is the subset of ISO 3166-2 which applies to Romania.
Each two-part code consists of the ISO 3166-1 code for Romania (RO) and a 1 or 2-character alphabetic sub-code, hyphenated together.
RO-AB
RO-AG
RO-AR
RO-B
RO-BC
RO-BH
RO-BN
RO-BR
RO-BT
RO-BV
RO-BZ
RO-CJ
RO-CL
RO-CS
RO-CT
RO-CV
RO-DB
RO-DJ
RO-GJ
RO-GL
RO-GR
RO-HD
RO-HG
RO-IF
RO-IL
RO-IS
RO-MH
RO-MM
RO-MS
RO-NT
RO-OT
RO-PH
RO-SB
RO-SJ
RO-SM
RO-SV
RO-TL
RO-TM
RO-TR
RO-VL
RO-VN
RO-VS