For what it's worth, I've received international calls in which the
*last* two digits were truncated in caller ID.For example, my Japanese cell phone (dual W-CDMA/GSM, roaming on US GSM networks) has received a few calls where the caller ID was
0118190402016. Breaking that down, we get 011-81-90-4020-16xx. 011 is the North American IDD prefix, 81 is Japan, 90 is mobile, and 402x-xxxx means that it's assigned to NTT DoCoMo.That number does not belong to any of my friends in Japan who would have my Japanese mobile number; plus they'd all know to send me email rather than trying to call since I'm currently in the USA. No message has been left on my voicemail, and its greeting is bilingual Japanese/English, so I don't think that it's a wrong number.
So, it's most likely a "wangiri".
"Wangiri" is a common form of spamming mobile phones used in Japan. The word is a contraction meaning "one ring, hang up"; the spammer calls your phone, lets it ring once, then hangs up. The idea is to leave the spammer's phone number in your call history to trick you into calling back.
Japan is a country in which the caller pays both to call a mobile phone and to place a call from a mobile phone. Thus, if you are foolish enough to call a wangiri back, you pay not only your mobile phone charges to make the call, but also the spammer's mobile phone charges!
In sending me a wangiri, the spammer just wasted the resources of NTT DoCoMo (his mobile company), Vodafone Japan (my mobile phone company), the international carrier(s) to the US, and T-Mobile in the USA to deliver a truncated (and hence useless) wangiri to someone who knows quite well not to call unknown numbers.
Vodafone Japan's instructions quaintly state the following about wangiri calls: "simply ignore it, never call back, and erase the record from call history. Answering or returning such calls may lead to you receiving threats or to become involved in an incident."
I wonder if Europe has similar problems, since they also practice caller pays.
-- Mark --