= Subtractive tare device
A \b[subtractive tare device] is a <tare device> whose operation reduces the weighing range available for net loads.<Non-automatic weighing instruments, Part 1>[OIML R76-1:2006(E), T.2.7.4, printed p11]{ref} Its zero display accounts for a load already present, while that load continues to occupy part of the instrument's capacity.
Consider a chosen model with <maximum weighing capacity> $\mathrm{Max}=10\,\mathrm{kg}$ and no additive tare capacity. If a container of <tare mass> $T$ is supported on the <load receptor>, the admissible <net mass> $N$ in this model satisfies
$$
N+T\leq\mathrm{Max},
\qquad
N_{\max}=\mathrm{Max}-T.
$$
With $T=2.5\,\mathrm{kg}$, the largest net load in this capacity budget is $7.5\,\mathrm{kg}$. Adding $8\,\mathrm{kg}$ after taring would produce <gross mass> $10.5\,\mathrm{kg}$, even though the desired net indication is below $10\,\mathrm{kg}$.
Changing to a $0.8\,\mathrm{kg}$ container would leave $9.2\,\mathrm{kg}$ available for <net mass> in the same model. This is a physical consequence of reducing the supported <tare mass>, rather than a benefit obtainable by repeatedly resetting the display.
An <additive tare device> is defined by retaining the net-load weighing range. Therefore the equation above is a model for subtractive tare and a shared gross-load bound, rather than a universal rule that every scale's printed $\mathrm{Max}$ includes every possible tare allowance. The chosen container, allowed tare range and instrument capacity must describe the same load configuration.
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