In Steve stuff, he use for every author/illustrator, a 700 field, with
$a containing the name and $e containing the role (author or illustrator)
In my UNIMARC manual, i can find :
700 : main responsability : $a as name, and $4 as title. I have no $e
subtag.
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$4 as a title? According to UNIMARC Manual
http://www.ifla.org/VI/3/p1996-1/uni7.htm
$4 Relator Code
The code used to designate the relationship between the person named in the field and the bibliographic item to which the record refers. The list of codes is to be found in Appendix C. Repeatable.
You may have old/misprinted manual.