key sth to sth
phrasal verb with key verb [ I or T ] uk/kiː/ us
usually passive to arrange or plan something so that it is suitable for a particular person or situation:
These products are keyed to the interests of very young children.
to relate something to something else, so that the two things change at the same time, or by the same amount:
The government entitlement programs are keyed to the rate of inflation.