It is not standby, nor equivalent to standby. Inventory must be available at the time of the change. No inventory, no standing by for no-shows.

AIRPORT SAME DAY CONFIRMED CHANGE FEE-
FOR TANGO PLUS -TP TYPE FARES ONLY-
PASSENGERS HOLDING CONFIRMED RESERVATIONS AND
TICKETS MAY CONFIRM EARLIER/LATER SAME DAY FLIGHTS
BETWEEN THE SAME ORIGIN/DESTINATION/STOPOVER
POINTS FOR A NONREFUNDABLE FEE OF CAD75/USD75
NOTE-
A. SEAT INVENTORY MUST BE AVAILABLE IN THE CABIN
APPLICABLE TO THE FARE CHARGED.
B. POLICY APPLIES FOR PASSENGERS NEXT OUTBOUND OR
INBOUND ONLY. CHANGES CANNOT BE MADE TO INBOUND
SEGMENTS BEFORE THE ORIGINAL TICKTED OUTBOUND HAS
BEEN FLOWN.
C. CONFIRMED CHANGE MAY ONLY BE MADE AT THE
AIRPORT ON THE DAY OF THE FLIGHT.
D. REGULAR FARE RULES APPLY - CHANGE FEES/ADCOL-
FOR ANY CHANGES WHICH DO NOT QUALIFY FOR THE
AIRPORT SAME DAY CONFIRMED CHANGE FEE.
E. SAMEDAY STANDBY NOT ALLOWED.