What normal form is violated here?
A telephone call is uniquely identified by telephone number and time of call. These candidate keys compose the composite primary key. There is an attribute/column “telephone location”.

telephone number|time of call | telephone location(precise)

Does it help if the telephone is mobile?

Just thinking about this may cause you sleepless nights but there is something to be learned.

I think you need to read this.

Thanks!
I already know the answer. I was supplying the question as a "machine" to lead neophytes into normalization.

It is an interesting question.

If you know something and want to show your knowledge then please do not post those here as questions. Better post those as an article ,that will really help the new members.

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