key something to something phrasal verb American English ( see also ↑ key )
1 . to make or change a system so that it works well with something else:
The daycare hours are keyed to the needs of working parents.
2 . if the level, price, or value of something is keyed to something else, it is related to it and they rise and fall at the same time:
Pensions are keyed to the rate of inflation.
⇨ ↑ keyed up