отпуск - vacation (payed days free of work)
It says that the person didn't use his right for vacation during graduation and according to the law his right is kept for him to use when he starts work at the place offered by the school (or college).

The bold sentence:
Лицам закончившим профтехучилище, время обучения в училище заносится в общий и непрерывный трудовой стаж.
The duration of studying vocational school (school which provides a professional qualification) is included at the working record (the record which is used to calculate the age of retirement).