That's right - just a period. So they're obviously able to create their own Caller ID, and thus possibly faking the number itself.
Amazing.
I've had no junk calls in two weeks. Then today, two within two hours, from (apparently) different sources. Same thing happened several times earlier this year. No calls for several weeks, then three or four in one day.
Will be interesting to see if I get a couple more today. That would seem to indicate a "centralized scheduling" of various telemarketing phone systems.