The card is to begin the hiring process. After you go and sign at Norfolk you will be given all of the paperwork(physical, application, etc). You will then be contacted for prescreening in which you will do the pt test and if you pass all of that you will continue with the oral board interview, psych test, drug test, etc. This day is very long. If you make it past this phase you will be contacted for a meeting with the psychologist and a background investigator will contact you. If all goes well you will be given a conditional offer of employment and notified of when the academy begins. I hope I didnt leave anything out.
On another note. The PT has gradually gone up to 3- 3 1/2 mile formation runs 3 times a week and the calistenics are pretty intense, basically pushing everyone to failure. This is nothing compared to what the SP goes through but it is getting many people to drop some pounds.
Hope this helped. I'll be happy to answer any other questions.