analyse the following extract in terms of tenor of discourse-formality,politeness,imoersonality,and accessibility.
Announcement from the librarian
It has beeen noted with concern that the stock of books in the library has been declining alarmingly. Students are asked to remind themselves of the rules for the borrowing and return of books, and to bear in mind the needs of other students.Penalties for overdue books in the future will be stictly enforced.
是分析,请看清楚点,不是翻译。