I am aware of at least one flying school that would take a jerry can around and bleed a few planes whenever the bowser was short :oh:

ATA 103 are the regulations that specify the criteria for defueling an aircraft and what can happen to the fuel afterwards.
The airline may permit you to defuel one aircraft and use it in another of their aircraft.
Some facilities have multiple empty tanks to enable storage of airline specific de-fueled JET-A. The fuel needs to pass standard checks receiving tests prior to being placed into the tank.
You can also send samples off to the labs for full checks to be carried out on the fuel and having it re-certified to be placed into bulk storage for resale/reuse. (takes about 3 days).
Offloading one airline and pumping into another is a definite no-no

ATA103 is an industry accepted standard in North America, but I have seen these procedures applied in the Middle East and Africa as well.

Most fuel suppliers use ATA103 as a standard for the training of their network of into plane suppliers (FBO's etc.) - BP used to have the best globally recognized training program out there