How to type an ‘@’ sign?

Long ago, some packages used to use the ‘@’ sign as a special character, so that special measures were needed to type it. While those packages are still in principle available, few people use them, and those that do use them have ready access to rather good documentation.

Ordinary people (such as the author of this FAQ) need only type ‘@’.

This answer last edited: 2011-08-16

This question on the Web: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=atsign