Delete items from smart lists

[jenv]

If I am viewing an item in a smart list, and try to delete it, nothing happens but a nasty noise telling me I can't. I must navigate to the library and click the item again (because moving to the library lost focus on the item). Requiring these extra mouse clicks seems unnecessary. Why not pop up a dialogue asking if I want to permanently delete the item from the Library or its Library-independent collection?

[sjk]

If I am viewing an item in a smart list, and try to delete it, nothing happens but a nasty noise telling me I can't.

Maybe Option-Delete will work?

[Nora]

You can't delete entries from a smart collection because the collections are assembled automatically by the program based on the criteria you have given it. If you don't want the entry to be part of the collection, you have to change the criteria or edit the entry so that the entry doesn't match the smart rules anymore.
To delete an entry from a smart collection AND your database entirely, use Option-Delete as sjk suggested.