Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!hplabs!otter.hpl.hp.com!otter!nt
From: nt@otter.hpl.hp.com (Nicolas Tripon)
Newsgroups: comp.unix.questions
Subject: Re: Inserting Blank Line into File (sed/awk/?)
Message-ID: <1170017@otter.hpl.hp.com>
Date: 19 Mar 91 15:57:13 GMT
References: <807@oss670.UUCP>
Organization: Hewlett-Packard Laboratories, Bristol, UK.
Lines: 3

sed 's/^\(Phone:.*\)$/\1\
/' file
(the first line ends with back slash followed by line feed).