Bearing, pertinence, and relevance all refer to the magnitude of the relationship between things. Something that makes you not want to buy a product can have just as much bearing on your decision as something that makes you want to buy it. "Negative bearing" isn't really a thing.

What is a reverse bearing?

(Surv.) the bearing of a back station as observed from the station next in advance.

How do you reverse a bearing?

One technique is to do the math. Add or subtract 180° from you forward bearing to get your back bearing. You want the result to fall between 0° and 360°, so if the forward bearing is less than 180°, add 180° to it, and if it's greater than 180°, subtract 180°. Calculating a back bearing.