Following the name of the champion(s): Indicates the number of times the competitor has held that title at that point.
[...]
Indicates a gap in the listing where title changes are not known.
<
Title was held or changed hands no later than this. In these cases, it is known that a competitor held the title at a certain time but not when he/she won it.
@
Order uncertain. Different titleholders may be known for the same year, for example, but it is not known who held the title before whom.
#
Unofficial or disputable claims. These are usually matches that certainly took place, but where there is doubt that the competitor shown should be recognized as a true title holder. These listings are also italicized.
World Junior Welterweight Title [unlineal / disputed versions]
* Bolded letters in the competitor's name, if any, indicate the surname/family name.
Jackie Berg
1930-02-18
London, ENG, GBR
Defeats Mushy Callahan for the (lineal) world title; loses to the lightweight champion Tony Canzoneri in a double title match on 31-04-24 in Chicago, IL, USA but continues to claim the title because of the lightweight limit in the match rather than the junior welterweight limit (The Brooklyn Daily Times, 31-08-03); again loses to Canzoneri on 31-09-10 in New York, NY, USA but continues to claim the title with the support of The Ring magazine (United Press, 32-12-11).
