What is the status icon that looks like a house? There is a strange icon that shows up in my status bar only when I'm at a certain restaurant. It looks like a cross between a house and wifi. 

I suspect it might be a free wifi hotspot or something related to a nearby phone store, but I can't find any information about it in manual for my phone.

See the following screenshot:
This is the icon that symbolises that the Verizon Network Extender is in use - could it be possible that the restaurant you visit has had one installed/set up?

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