North Korean standard language or Munhwaŏ (Chosŏn'gŭl: 문화어; Hancha: 文化語) is the North Korean standard version of Korean language. Munhwaŏ was adopted as the standard in 1966. The adopting proclamation stated that the Pyongan dialect spoken in the North Korean capital Pyongyang and its surroundings should be the basis for Munhwaŏ; however, in practice, Iksop Lee and S. Robert Ramsey report that Munhwaŏ remains "firmly rooted" in the Seoul dialect, which had been the national standard for centuries. Most differences between the North and South Korean standards are thus attributable to replacement of Sino-Korean vocabulary and other loanwords with pure Korean words, or the Northern ideological preference for "the speech of the working class" which includes some words considered non-standard in the South.