^Benjamin represented Antigua officially only until 30 December 2016, when his personal best was 49.82, but did not represent the USA until 3 October 2018.[2]
^Aleksey Bazarov's personal best of 49.33 of June 1988 is not an Israeli NR as he represented the USRR (Moldova) before 1991.
^Eusebio Haliti's personal best of 49.85 of 28 July 2013 is not an Albanian NR as he represented Italy since 2012.
^Edivaldo Monteiro's personal best of 49.10 set in June 2004 is not a Guinea-Bissau NR as he represented Portugal after 1999.
^The personal best of Tatyana Zubova (married name: Tatyana Pavlova) is 54.34 but this is not listed as the Uzbeki NR in the World Athletics Statistic Handbook.
^Irina Lenskiy emigrated from Ukraine to Israel in 1999, so personal best time of 55.43 run in 1996 is not the Israeli record
^Nusrat Ceesay transferred from Britain to Gambia on 31 May 2011, so her personal best of 57.13 in Birmingham in July 2009 is not a Gambian NR.
^Questionable. No other 400 m hurdles result of Harutyunyan is known below 1:03.13, which she ran a few weeks later at the Olympic Games
^ abAmerican-born Busiwa Asinga's ran her personal best of 58.07 in 2021 when she represented Zambia, her mother Ngozi Mwanamwambwa's birth country and the place she grew up. From May 2023, she and her brother Issam Asinga have competed for Suriname, her father Tommy Asinga's birth country. [266][267]