Bug introduced in 9.0 or earlier and fixed in 10.3
NotebookWrite[EvaluationNotebook, Cell["Foo", "Text", Copyable -> False, CellTags -> "example"]]; NotebookFind[EvaluationNotebook, "example", All, CellTags]; NotebookDelete;
Execute that. You'll hear a beep, and the generated cell does not disappear. The Help menu's "Why the beep?" command helpfully explains that
"The material you tried to copy had the option
Copyable->Falseset, preventing it from being copied to the clipboard."
Wait, what? I was trying to delete, not copy. The cell has
Deletable->True by default.
My question is: Why does
NotebookDelete fail on a cell for which
Copyable->False? It doesn't copy. (I checked. With
Copyable->True, the delete succeeds, and my system clipboard contains what it previously had, not the deleted cell.)
Is this perhaps a bug? (I'm using Mathematica 10.2.0.0 on OS X.)