The $A tag is used only on the title page to indicate the name of the author or authors.
How it works
$A is added before the author’s name.
$T His Last Bow
$ST A Reminiscence of Sherlock Holmes
$A Arthur Conan Doyle
$P John Murray Publishers, London, England
There can be more than one author so the $A tag can be used more than once, or can contain multiple author names.
$A David Jones
It can also be used to indicate others involved in the preparation of the book, such as editors.
$A Series editor: Patrick Murphy