What characteristic would NOT be a sign of a potential dangerous package?

Standard postal markings should not be considered a sign of a potentially dangerous package because these markings indicate that the item has been processed and accepted by postal services. In many cases, packages that arrive with standard postal markings have gone through security checks at postal facilities, which minimizes the likelihood of them being hazardous.

On the other hand, excessive sealing materials, unusual weight or size, and strange odors are all red flags that could indicate a package may pose a danger. For instance, a package excessively sealed with tape may suggest a person is attempting to conceal its contents. An unusual weight or size might indicate that something is not quite right, as it may not conform to expected dimensions or weights for typical packages. Lastly, strange odors can be a clear warning sign of hazardous materials or substances. Therefore, the presence of standard postal markings is a reassuring factor, distinguishing legitimate mail from suspicious items.