subject

Get the document subject.
[read-only property] subject([out, retval] BSTR *val)
This property contains the value of the Subject field.

This property throws an error if the requested entry doesn't exist in the info dictionary.

Reading this property is equivalent to calling:

pdf.getInfoString("Subject")
VB6:
s = pdf.subject MsgBox "subject = " & s
getInfoString
title
keywords
author
creator
producer