It's a barely documented and somewhat dubious feature.

Personally I find it an useful feature. However I hardly ever remember having used it: more precisely most of my warnings and errors are meant for the users of some script. Thus I end them with "\n". In the rare case I have some that are meant for people working on the script itself, I don't append it. A tiny example was posted here.

In reply to Re^2: Where does <GEN1> come from? by blazar
in thread Where does <GEN1> come from? by mnooning

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