Zero ohm resistor tolerance?

If you look at a "proper" data sheet (example: http://www.yageo.com/documents/recent/PYu-RC0603_51_RoHS_L_4.pdf) you'll usually find that the zero ohm resistor is defined separately using something like < 0.05R.

In this case, you're looking at a more or less automatically generated set of data which is probably more relevant to the other resistors in the range. Multicomp in this case refers to multiple sources so the parts could be coming from anywhere; the data in this case is fairly general and is most likely the lowest common denominator for a variety of alternative devices.

Yeah, that doesn't make sense.

http://en.wikipedia.org/wiki/Zero-ohm_link

The resistance is only approximately zero; only a maximum (typically 10–50 mΩ) is specified. Thus, a fractional tolerance (as a percentage of the zero-ohm ideal value) would be infinite and is not specified.

Apparently someone got carried away and thought that just because it looks like a resistor, it should have a tolerance like one.

Well, it's really just a resistor shaped piece of wire, so the only thing that would make much sense would be to spec 'not more than X amount of resistance', where X would presumably be a few milli-ohms.

If it was absolutely necessary to state it as a tolerance, it wouldn't be incorrect to say X/2 +/- 50%, but who has ever heard of a 50% tolerance part?