On a resistor, what do the + and - signs indicate?

The + and - signs on a resistor are typically used to indicate the polarity of the resistor if it is a type that has specific directionality or if it is part of a specific application within a circuit, such as in a voltage divider or biasing arrangement. However, in general contexts, resistors are passive components that don't have polarity.

While tolerance reflects how much the resistor's actual resistance can deviate from its specified value, it is usually denoted with a percentage or color code rather than with + and - signs.

The signs can sometimes denote the side of the resistor that connects to a higher potential or lower potential voltage in certain configurations, but this does not inherently relate to main functions such as voltage ratings or temperature coefficients, which have different indicators and methods of identification.

Therefore, the presence of + and - signs can be misleading if one is not considering the context or specific application of the resistor. In standard resistor usage, one would expect more straightforward markings indicating resistance values and tolerances without the necessity for polarity.