Apparating inside Hogwarts

[cmarsmith]

No: HPFGUIDX 59532

Please forgive me if this has been covered before. 

Hermione mentions time and again that one cannot Apparate in 
Hogwarts. However we know that several creatures/people have done so 
(Dobby, Fawkes, possibly Dumbledore).

It recently occurred to me that food is (apparently) apparated from 
the kitchen to other places within Hogwarts, primarly the Great Hall, 
but also other places such as Snape's office in CoS.

Does anyone know if canon merely prohibits Apparating in to and out 
of Hogwarts but not from one place within the castle to another place 
within the castle? We are obviously ment to believe that this is not 
possible, but do we know that it's not the case?

Thanks,
Charlie