County or not county ? 

 The below former counties of South Pyongan were merged with Nampo in 2004 and are administered as part of that city:
 Chollima-guyok (천리마군/千里馬郡)
 Kangso-guyok (강서군/江西郡)
 Ryonggang County (룡강군/龍岡郡)
 Taean-guyok-gun (대안군/大安郡)

This looks weird. Each former county was formerly named 군. When merged wit Nampo, some were renamed 구역. The parenthetical Hangul names are the former names (why not, this can be an editorial choice). But the Roman names should be either all new or all former. We should have either Ryonggang-gun or Ryonggang-guyok (according to the actual name). And either Taean-guyok or Taean-gun. But what could be a guyok-gun ?