What tool located on the status bar indicates whether a document contains spelling?

The tool on the status bar that indicates whether a document contains spelling errors is usually a spelling icon. This icon often looks like a "ABC" or a "check mark".

Here's how it works:

* Red icon: This means there are spelling errors in the document. Clicking on the icon might reveal a list of the errors or offer to check the spelling.

* Green icon: This usually means the document has no spelling errors, or at least none that the software has detected.

The specific appearance of the icon and its functionality can vary slightly depending on the software you're using (e.g., Microsoft Word, Google Docs, etc.).