The 'E' booking class seems to be used for ex. Canada unrestricted fares - tried to book YYZ->SEA->YYZ on July 14/15 and got this:

Class: Coach
Fare Basis Code:
EBIZ
Booking Class: E

...and of course it does not qualify for the complimentary NF upgrades... the B-fare is a whooping $2700....I ended up calling UA to get more info on this fare and the two agents I spoke to had no idea what this booking class was all about...

The fare rules are:


0. APPLICATION AND OTHER CONDITIONS
RULE - 013/2015
UNLESS OTHERWISE SPECIFIED
NORMAL FARES
APPLICATION
TYPES OF TRANSPORTATION
THIS RULE ALSO APPLIES TO JOINT TRANSPORTATION.
CAPACITY LIMITATIONS
THE NUMBER OF SEATS WHICH CARRIER SHALL MAKE
AVAILABLE AT FARES GOVERNED BY THIS RULE ON
ANY GIVEN FLIGHT WILL BE DETERMINED BY CARRIERS
BEST JUDGEMENT AS TO THE ANTICIPATED TOTAL
PASSENGER LOAD FACTOR ON EACH FLIGHT AND FARES
WILL NOT NECESSARILY BE MADE AVAILABLE ON ALL
FLIGHTS.
RULES NOT APPLICABLE
6030/ 6040 - TOUR CONDUCTORS
6055/ 6065/ 6070 - PASSENGER SALES AGENTS
5. ADVANCE RES/TICKETING
FOR -B TYPE FARES
RESERVATIONS ARE REQUIRED FOR ALL SECTORS.
NOTE -
FARES WHICH DO NOT HAVE ANY RE-ROUTING/FLT CHG
RESTRICTIONS AND ARE NOT SUBJECT TO SERVICE CHRGS
STANDBY ARE PERMITTED.
8. STOPOVERS
NONE UNLESS OTHERWISE SPECIFIED
9. TRANSFERS
FOR ONE WAY FARES
4 TRANSFERS PERMITTED.
10. PERMITTED COMBINATIONS
FOR ONE WAY FARES
ADD-ONS NOT PERMITTED.
END-ON-END PERMITTED. VALIDATE ALL FARE COMPONENTS.
TRAVEL MUST BE VIA POINT OF COMBINATION.
OPEN JAWS/2-COMPONENT CIRCLE TRIPS/MULTI-COMPONENT CIRCLE
TRIPS
FARES MAY BE COMBINED ON A HALF ROUND TRIP BASIS WITH
ANY FARE FOR ANY CARRIER IN ANY RULE AND TARIFF.
-TO FORM SINGLE OR DOUBLE OPEN JAWS/2-COMPONENT CIRCLE
TRIPS/MULTI-COMPONENT CIRCLE TRIPS.
OPEN JAWS/ROUND TRIPS/CIRCLE TRIPS NOTE -
WHEN COMBINED ON A HALF ROUND TRIP BASIS WITH
A ROUND TRIP FARE TO FORM ROUND/CIRCLE/OPEN
JAW TRIPS--THE MOST RESTRICTIVE PROVISIONS
APPLY. THESE INCLUDE MIN/MAX STAY-
RESERVATIONS/TICKET REQUIREMENTS -STOPOVER
PROVISIONS-CANCEL/CHANGE PENALTIES/SERVICE
CHARGES OR COMBINATION PROVISIONS.
NOTE - THE CITY PAIRS BELOW ARE CONSIDERED THE SAME POINT-
BWI-WAS FLL-MIA FLL-PBI MIA-PBI BUR-LAX BUR-ONT
BUR-SNA LAX-ONT LAX-SNA ONT-SNA OAK-SFO OAK-SJC
SFO-SJC EWR-HVN EWR-ISP EWR-NYC EWR-HPN HVN-ISP
HVN-NYC HVN-HPN ISP-NYC ISP-HPN NYC-HPN
12. SURCHARGES
UNLESS OTHERWISE SPECIFIED
A SURCHARGE OF CAD 7.50 OR USD 4.65 WILL BE ADDED TO THE
APPLICABLE FARE FOR TRAVEL.
NOTE -
THIS IS A NAVIGATION SURCHARGE. THE SURCHARGE
APPLIES IN ADDITION TO ALL OTHER CHARGES AND IS
NOT SUBJECT TO ANY DISCOUNT.
AND - A FUEL SURCHARGE OF CAD 14.30 OR USD 9.30 ONE WAY
WILL BE ADDED TO THE APPLICABLE FARE.
NOTE -
THE SURCHARGE APPLIES IN ADDITION TO ALL OTHER
CHARGES AND IS NOT SUBJECT TO ANY DISCOUNT.
15. SALES RESTRICTIONS
UNLESS OTHERWISE SPECIFIED
TICKETS MAY BE ISSUED BY MAIL/PTA/MECHANICAL MEANS.
TICKETS MAY NOT BE ISSUED BY SELF TICKETS/WRITE-YOUR-OWN
TICKETS. PTA CONSTITUTES TICKETING.
16. PENALTIES
UNLESS OTHERWISE SPECIFIED
NOTE -
1. WHOLLY UNUSED TICKETS -
CHANGES TO ORIGINATING FLIGHT -
WHOLLY UNUSED TICKETS ARE FULLY REFUNDABLE.
CHANGES ARE PERMITTED AT ANYTIME.
IF CHANGE IS MADE TO ORIGIN/DESTINATION/STOP-
OVER POINT/BOOKING CODE OR CHANGE VIOLATES
RULES OF ORIGINALLY TICKETED FARE-TICKET MUST
BE REPRICED AT CURRENT FARES APPLICABLE TO
CHANGED ITINERARY. CHANGES MUST BE MADE AND
TICKET REISSUED BY THE ADVANCE PURCHASE OF
THE NEW FARE.
A. IF NEW FARE IS HIGHER IN VALUE -
COLLECT FARE DIFFERENCE
B. IF NEW FARE IS LOWER IN VALUE -
THE RESIDUAL AMOUNT WILL BE REFUNDED TO
ORIGINAL FORM OF PAYMENT.
2. WHOLLY UNUSED TICKETS -
CHANGES TO OTHER THAN THE ORIGINATING FLIGHT
WITH NO CHANGE TO ORIGIN/DESTINATION/STOPOVER
POINTS -
CHANGES TO OTHER THAN THE ORIGINATING FLIGHT
MAY BE MADE ANYTIME WITHOUT REGARD TO THE
ADVANCE PURCHASE REQUIREMENT PROVIDED CHANGE
MEETS ALL OTHER RULES OF THE TICKETED FARE
AND ORIGINAL BOOKING CODE IS AVAILABLE.
IF CHANGE IS MADE TO ORIGIN/DESTINATION/
STOPOVER POINT/BOOKING CODE OR CHANGE
VIOLATES MIN/MAX REQUIREMENT OF ORIGINAL
TICKETED FARE - TICKET MUST BE REPRICED USING
CURRENT FARES APPLICABLE TO CHANGED
ITINERARY. CHANGES MUST BE MADE AND TICKET
REISSUED BY THE ADVANCE PURCHASE OF THE NEW
FARE.
A. IF NEW FARE IS HIGHER IN VALUE -
COLLECT FARE DIFFERENCE.
B. IF NEW FARE IS LOWER IN VALUE -
THE RESIDUAL AMOUNT WILL BE REFUNDED TO
ORIGINAL FORM OF PAYMENT.
3. PARTIALLY USED TICKETS -
NO CHANGE TO ORIGIN/DESTINATION/STOPOVER POINTS
CHANGES MAY BE MADE TO OTHER THAN THE ORIG-
INATING FLIGHT ANYTIME WITHOUT REGARD TO THE
ADVANCE PURCHASE REQUIREMENT PROVIDED CHANGE
MEETS ALL OTHER RULES OF THE TICKETED FARE
AND ORIGINAL BOOKING CODE IS AVAILABLE.
4. PARTIALLY USED TICKETS -
CHANGE TO ORIGIN/DESTINATION/STOPOVER POINTS -
IF CHANGE IS MADE TO ORIGIN/DESTINATION/
STOPOVER POINTS OR IF CHANGE VIOLATES MIN/MAX
REQUIREMENT OF ORIGINALLY TICKETED FARE OR
ORIGINAL BOOKING CODE IS NOT AVAILABLE -
SUBTRACT THE CURRENT APPLICABLE FARE FOR
PREVIOUSLY FLOWN SEGMENTS AND REFUND ANY
RESIDUAL AMOUNT TO ORIGINAL FORM OF
PAYMENT. ANY CURRENT APPLICABLE FARE MAY
BE USED TO CALCULATE PREVIOUSLY FLOWN
SEGMENT INCLUDING FARE MEETING SAME
QUALIFICATIONS SUCH AS ADVANCE PURCHASE
OR DAY OF WEEK APPLICATION OF ORIGINAL
FARE. NEW FARE MUST BE EQUAL TO OR HIGHER
THAN THE BOOKING CODE OF THE ORIGINALLY
FLOWN FARE BASED ON THE FOLLOWING
HEIRARCHY. ISSUE NEW TICKET FOR CONTINUING/
RETURN ITINERARY.
P/F/C/D/Y/A/B/E/M/U/H/Q/V/W/S/T
----
WHEN THESE FARES ARE COMBINED ON A HALF ROUND TRIP
BASIS WITH PENALTY OR RESTRICTED FARES TO FORM A
RT/CT/OJ ITINERARY THE MOST RESTRICTIVE PROVISIONS
WILL APPLY.
EXCEPTION -
FARES COMBINED END-ON-END ON THE TICKET//IE
FARES THAT COULD STAND ALONE IF ISSUED ON A
SEPARATE TICKET// MAY BE CHANGED SEPARATELY.
----
PASSENGERS HOLDING CONFIRMED RESERVATIONS AND
TICKETS MAY STANDBY FOR EARLIER/LATER SAME DAY
FLIGHTS BETWEEN TICKETED CITY PAIRS AT NO
ADDITIONAL COST PROVIDED THERE IS NO CHANGE TO
PROVISIONS OF FARE RULES. IN ADDITION TO THE
ORIGINAL AIRPORT OF DEPARTURE/ARRIVAL PASSENGERS
MAY CHECK IN AND STANDBY TO/FROM AIRPORTS LISTED
BELOW UNLESS RESTRICTED BY THE AIRPORT PROVISIONS
OF THE FARE.
CITY AIRPORT
CHI CGX/ORD/MDW
NYC JFK/LGA
WAS DCA/IAD