* Yalkut Yosef (vol 2, p. 562), however, writes that for Sephardim, it’s permitted to tie a necktie if it is going to be untied within a week.
* Rav Moshe Feinstein (cited by 39 Melachos, footnote #42), Rabbi Eliezer Waldenburg (cited by [[Shabbat]] VeHilchoteha p. 221), Menuchat Ahava (vol 3, 14:13), and Or Letzion 2:47:21 permit [[tying]] a necktie and don’t specify which type.
* Rabbi Mordechai Willig ([http://www.yutorah.org/lectures/lecture.cfm/726909/Rabbi_Mordechai_I_Willig/Hilchos_Shabbos_5761_-_KosherMatir_#1 “Hilchos Shabbat 5761 Kosher#1”] min 90-4) says that even according to those who consider a tie to be a knot, it is permitted to make a tie if one has intent to undo it within 24 hours. This is even true for a person who usually leaves their tie tied. Although the Beiur Halacha
D”H HaKosher writes that one’s personal intent to undo it within 24 hours is ineffective when the way of the world is to leave a knot tied, Rabbi Willig explained that this case is not similar because some do untie their ties everyday. The 39 Melachos (footnote #41) has the same idea.
* [[Shabbos]] Home (p. 221) writes that if the tie is totally undone by pulling out the narrow end (“Four in Hand”) it may be tied forever, and if it isn’t totally undone when narrow end is pulled out (“Windsor”), some permit [[tying]] it forever, and some say it’s only permitted if one intends to undo it within 24 hours.
* Orchot [[Shabbat]] (vol 1, p. 338) argues that the first type (“Four in Hand”) is only permitted if one intends to untie in within 24 hours, but the second type (“Windsor”) is questionable.