Value Signal
Also known as: Signal
A single observable measure that indicates something about a property's value, with a named data source and a stated limit.
A value signal is one measurable thing, documented individually: what it measures, where the data comes from, what it indicates about value, what moves it, and what it does not prove. The signal inventory is the full set, grouped by dimension.
Signals are kept separate rather than combined because they move independently. A property can gain discovery and lose commercial intent in the same month, and any average of the two describes neither.
A signal with no stated limit is a slogan. Every entry in the inventory carries what it cannot prove, because the failure mode of measurement work is not missing a signal, it is trusting one past what it supports.