Each employment office had its own guide cards for its work book card indexes. With the help of these guide cards, the employment office staff marked the numbered index card tabs on the front and back of the work book cards with different colored lines. This allowed them to see at a glance the professional skills of the person for whom the card had been created. A red line stood for very good skills, and a blue line for minimal skills.
It was standard practice across the German Reich to enter the age of the person in tab 26. Their marital status followed in tab 27: A straight red line meant the person was married, a red horizontal line meant they were single, and a blue line indicated dependents the person cared for financially. However, not all cards were filled out according to the regulations, as there are work book cards without these lines and entries. Furthermore, as the war progressed, individual employment offices complied less and less with the escalating number of decrees and regulations.