Daytime - shake your head and transmit "Suspend cat number X" on the tower freq.
Nighttime - turn off your lights and transmit same on departure.

After each, be ready to go fly until the Cat officer or Safety PO walks in front of the aircraft and signals you to pull the power back.

Pretty much, once you salute/turn on the lights, you're going unless someone on the deck suspends you.

HTH
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