Perhaps the correct phrase to use is "temporary custodians" or "transitory authority".

And, he said, some temporary custodians gave such good service that he got letters from principals begging to keep them on.

Much of the merchandise is looted, its temporary custodians eager to pocket something for their trouble and to move the goods along.

On arrival, he impulsively asks for work and is hired as a temporary custodian.

The Saudis clearly hope that they will be temporary custodians for the prisoners and refugees.

But the Tayledras considered themselves no more than temporary custodians of their power.

All but lost is the fact that any information they possess belongs to the public; they were nothing more than temporary custodians.

"My hope is that there are enough people here who will understand they rule as temporary custodians of this place."

The elected office generally holds a greater deal of respect than the man or woman who is temporary custodian of that title.

Unlike many collectors, the Gelmans saw themselves as temporary custodians of the art they owned.