It means your phone is locked because you've entered your PIN (Personal Identity Number) wrongly three times. You need to call your network provider (from another phone) and ask them for the PUC (Phone Unlock Code)
if you mean your phone shows signal bars but says limited service (i.e no display of network logo) then this is generally when your service provider does not have signal in your area but your phone recognises that there is a cellular signal available and would use that in emergency call situations, hence why some sony's state "emergency calls only".Don't quote me on it but as either a gentlemans agreement or obligation by law all phone must be capable of making emergency call if possible when signal is present regardless of provider.
In the Settings menu usually where it says Calls. Depends on the phone check the manual.
If your cell phone is displaying "PUK blocked" and suggesting an emergency call, it means you have entered the wrong Personal Unlocking Key multiple times and your SIM card is now blocked. You need to contact your mobile network provider to get the PUK code to unlock your SIM card. The emergency call option is usually available for making calls to emergency services even when the phone is locked.
you're out of luck... sorry.
Your girlfriend's cheating
I think it means that you're in an restricted area where the phone can not pick up signals for incoming and outgoing phone calls.
Go to her house and say she is right to what ever she says. She is probably mad r she just has her phone off or something.
Oh that is just a prank phone call. They do other prank phone calls like, I think 'the end is near' or something similar. Don't worry about it.
SOS is the international distress code in Morse Code, devised for the earliest wireless communication because the signal was easily recognized in any language (...---...). In more modern times, people have made up many expressions to correspond to the letter combination; but in most cases, it still means 'help' or 'emergency'.
It means she wants you to actually call her on the phone and have a real conversation instead of just texting her.
A land-line phone number is just a house phone. you know.. the kind that you don't carry around with you when you go places.