It is known from records that Nyoingo was chosen from among several proposed candidates, and the decision was based not only on the ridai or monin name, but also whether the characters were good or not or whether it resembles an unlucky predecessor, and it was considered from various angles such as not repeating an existing title.
女院号の決定には、まず複数の候補が挙げられた中から選ばれたことが記録から判り、選定に当たっては里第名や門院名だけでなく、字が良いかどうかや不吉な先例に似ていないか、また既に存在する院号と重複しないか等、様々な角度から検討された。