ITA is a useful tool!

http://matrix.itasoftware.com/cvg/dispatch/prego (login as guest)

Following is from:
http://www.flyertalk.com/forum/showthread.php?t=327261

First up: how to specify the booking code

The extensions to the routing language are accessed by postpending commands after a '/'. There's a wide set of commands available, but there's no description of them available on the ITA web site. Unfortunately, each command applies only to one part of the trip, so they must usually be entered in each box.

CONSTRAINING BOOKING CODES:

Command is: "f bc=X" or "f bc=X|bc=Y|..."
Ex: Limit each part of the trip to travel on United and booking in the
L booking-code:
from: BOS:: ua+ / f bc=l
to : LAX:: ua+ / f bc=l
Or with multiple booking-code choices and no airline restriction:
from: BOS::/ f bc=l|bc=m|bc=y
to : LAX::/ f bc=l|bc=m|bc=y


Here's another unpublished feature of the ITA software. This one allows you to specify the fare basis code.

I'm no expert on fare basis codes, but I suspect this will be useful to some FTers.

The extensions to the itasoftware routing language are accessed by postpending commands after a '/'. There's a wide set of commands available, but there's no description of them available on the ITA web site. Unfortunately, each command applies only to one part of the trip, so they must usually be entered in each box.

CONSTRAINING FARE BASIS CODES:

Command is: "f CC.AAA+BBB.FFFFF" or "f CC.AAA+BBB.FFFFF|..."
where CC is carrier code, AAA and BBB are fare origin
and destination city, FFFFF is fare basis code

Ex: fare only with NW BOS-LAX YUP fares:
from: BOS::/ f nw.bos+lax.yup
to : LAX::/ f nw.bos+lax.yup

Ex: fare with either YUP or F fares on any airline and between any
points:
from: BOS::/ f ..yup|..f
to : LAX::/ f ..yup|..f

Ex: fare using only "through" fares
from: BOS::/ f .bos+lax.
to : LAX::/ f .bos+lax.

Ex: fare using only NW YUP fares or UA F fares:
from: BOS::/ f nw..yup|ua..f
to : LAX::/ f nw..yup|ua..f


PREVENTING AIRLINES

Command is "-airlines XX ..."
Ex: prohibit Jet Blue or Delta
from: BOS ::/ -airlines B6 DL
to: LAX ::/ -airlines B6 DL

RESTRICTING TO AIRLINES

Command is "airlines XX ..."
Ex: consider only Jet Blue or Delta
from: BOS ::/ airlines B6 DL
to: LAX ::/ airlines B6 DL

LIMIT DURATION OF ITINERARY, IN MINUTES

Command is "maxdur XXX"
Ex: no more than 5hrs for each part of trip
from: BOS ::/ maxdur 300
to: LAX ::/ maxdur 300

PREVENT OVERNIGHT STOPS, AIRPORT CHANGES, REDEYES, PROPELLOR PLANES,
TRAINS, HELICOPTERS, ANY KIND OF SURFACE TRAVEL
Commands are "-overnight", "-change", "-redeye", "-prop", "-train", "-helicopter", "-surface"
Ex: no overnight stops, no airport chanes, no redeyes, no propellor planes
from: BOS ::/ -overnight, -change, -redeye, -prop
to: LAX ::/ -overnight, -change, -redeye, -prop

SET MINIMUM OR MAXIMUM TIME FOR CONNECTIONS, IN MINUTES

Commands are "minconnect XX", "maxconnect XX"
Ex: no less than one hour, no more than two hour connections
from: BOS ::/ minconnect 60, maxconnect 120
to: LAX ::/ minconnect 60, maxconnect 120

EXTRA CONNECTION TIME

Command is "padconnect XX"
Ex: require at least 20 minutes more than airline recommended
minimum connection time
from: BOS ::/ padconnect 20
to: LAX ::/ padconnect 20

PUTTING LOTS OF THINGS TOGETHER

Separate with commas.
Ex:
from: BOS :: UA UA / f bc=l|bc=y, -redeye, -prop
to: LAX :: UA+ / f ua.bos+lax.yup, padconnect 20, -overnight

Not all meta search engines are equal!

Meta search engines such as DoHop.com constructs multiple tickets to provide best fare. Example: BLR-GAU on DoHop & Kayak: