Union Book

I didn't know what a union book was, and it's very important to Jack - it's "what's been keepin' you [Jeanann] alive those fifteen years." Here's what I found out:

When someone joined a union in the mid-20th century, they would get a union book: a book with lots of blank pages. Every month that you pay your union dues, you get a stamp, and so it records your membership with the union. It says what position you have in the union, i.e. what job you fulfill, and when you started with the union. However, these days it is not a book with stamps but a card - but the text of PIG dictates that it is an actual book.