Is there a way to retrieve Custom document properties?

You can use the 'doc' object's 'info' property to set and read some of the document's properties, including the creation and reading of custom properties.

You can use:

for (var i in this.info)
console.println(i + ": "+ this.info[i]);

To list the property name and value for the properties of a PDF.

The following code:

var docTitle = this.info.Title;
this.info.Title = "JavaScript, The Definitive Guide";
this.info.ISBN = "1-56592-234-4";
this.info.PublishDate = new Date();

Will add the custom properties of 'ISBN' with a value of "1-56592-234-4" and 'PublishDate' with the current date and time and set the standard property 'Title' witha value of "JavaScript, The Definitive Guide".

More infromation is in the Acrobat JS API Reference.

Excellent! Thank you for the speedy reply.