- Note that regional variations exist for the upper left component of this character (戸 in Japan, 戶 in Taiwan, Korea, 户 in China, Hong Kong and Vietnam). In the Kangxi dictionary, the component is written 戸 similar to the Japanese form.
- An alternative form 啟 (U+555F) exists which is the preferred form used in Hong Kong and Taiwan.
啓 (radical 30, 口+8, 11 strokes, cangjie input 竹大口 (HKR) or 戈大口 (IKR) or X竹大口 (XHKR), composition ⿱⿰戸攵口(J) or ⿱⿰戶攵口(TK) or ⿱⿰户攵口(GHV or U+2F843))
- KangXi: page 195, character 17
- Dai Kanwa Jiten: character 3820
- Dae Jaweon: page 416, character 16
- Hanyu Da Zidian: volume 1, page 646, character 12
- Unihan data for U+5553