Important condition for attending the defence is returning the student's card to the examination board.
If you pass the defence we'll keep your student card.
If you lost your ID by any reason you are obliged to inform the school. If you didn't manage to ask for duplicate - you'll be asked to fulfill the statement which is accesssible at the examination board.
If you are studying on the second major you also need to fulfill the appropriate statement.
The rights for owning the student cards have only students holding the rights of SGH Warsaw School of Economics. It means that with the moment of taking the diploma exam or being removed from the list of students there is an obligation for returning student card (due to the § 5 point 2 of Regulation of Ministry of Science and Higher Education of November 2nd, 2006).