Originally Posted by
sario
Is it possible to search not only booking code but also single, determined fare?
Sort of. It is possible to filter the results by a fare, but actually ITA doesn't "search" by the fare.
To find results covered by BA fare IM0R (any route), use (goes at the end of the advanced routing box):
/f BA..IM0R
To find results covered by IL28SALE (issued by any carrier on any route) use
/f ..IL28SALE
To find results covered by BA fare AAPUK9 on LONSAO, use
/f BA.LON+SAO.AAPUK9
To combine with the alliance flag /allinace oneworld (or whatever), use a semicolon instead of a slash
The reason the distinction between filtering and searching exists, is that in some cases ITA does not find the cheapest fare covering the sectors right away (particularly with complex multicity itineraries) and you want to give it a helping hand so that more results are returned matching the fare.
Unfortunately in that situation you will get "no flights found". I discussed it with
ITA Hacker who filed a bug report but I was told it was a low priority to fix.