In an example, a method comprises fabricating a first validation device for association with a first replaceable print apparatus component. The device may be to form part of circuitry arranged on the first replaceable print apparatus component, and may provide an associated electrically detectable characteristic which varies with the position of at least part of the first validation device. The electrically detectable characteristic may be measured and data indicative of the characteristic may be stored in a first memory. The first replaceable print apparatus component comprising the first device and the first memory may be assembled.