package.preload...

[duck <duck@...>]

For the sake of exactness, should the require() function in compat-5.1
remove items from package.preload once they have been promoted to 
package.loaded status? 

Whilst this doesn't matter, given the way require() is implemented, it 
seems wrong that a library that is already loaded should still have its 
initialisation function in the "preload" table. Or is it envisaged that 
packages might get unloaded and reloaded later, or that they might 
get loaded more than once?