What's Valuable Then?

Very often,we could see signboards at public places,in library,shopping mall,car park,and so on....which writes:"Do Not Leave Valuable Belongings".

Fine,I get that.Then,today,I go to my school library and the same signboard shows the same message here.But 10 minutes after that I get annoyed.

Time for a llittle summary for my lovely school library info:
Student capacity for first floor=Less than 100 person
      ""       ""          second floor =Even lesser~~

Outside of the library there are drawers for students.I must emphasize the signboard's message:"Do Not Leave Your Valuables Here","The Library will not br responsible for any losses".~~

#$#%#%?"{%$#$%!@#*O&..........

As study week's approaching,most of the time the library is congested with students,so how about the rest and their belongings?Where are we gonna put our things then?No bags inside the library,no food and drink in the library,no unidentified objects are allowed in the library,bla bla bla...

And for our good sake,then you define for us,what is meant by valuables huh@.@

Such a lack of intellectual acuity and irony rules ever~!