Am I missing something?
I can use the title search to search WBC/WBA etc and also the NBA World and NYSAC World, but not "World".
Example. If you search WBC heavyweight you go as far back as 1970 (understandable), but if you look at Ali's record, it's obvious he held the WBA version, but pre Terrell (and formation of WBA) he held the "World heavyweight title" as did Liston, Patterson, Marciano and Louis etc...so why can't you search using that title description?
Using title search for "World title"
There is though. Before the NBA split away and finally became the WBA, there was just one world title and it was referred to as "World title". No undisputed, no lineal, no nothing. Just World title. Look back in all the old boxing mags from the 30s onwards, look at the all the record books (BBBoC Yearbooks, IBHOF yearbooks, Ring yearbooks etc) they all refer to it as "world title". Boxrec does too:
1965-05-25 206 Sonny Liston 215¼ 35-2-0
St. Dominic's Hall, Lewiston, ME, USA W KO 1 15 Wiki Biography
~ Time: 2:12 | Referee: Jersey Joe Walcott | Judge: Coley Wallace | Judge: Russ Leonard | Judge: Joe Colvin ~
World Heavyweight Title
Attendance: 2,434
1965-05-25 206 Sonny Liston 215¼ 35-2-0
St. Dominic's Hall, Lewiston, ME, USA W KO 1 15 Wiki Biography
~ Time: 2:12 | Referee: Jersey Joe Walcott | Judge: Coley Wallace | Judge: Russ Leonard | Judge: Joe Colvin ~
World Heavyweight Title
Attendance: 2,434