Hi Bill,

The little black triangle in the upper left corner of a cell is called a "smart tag". It appears when Excel detects a potential error or inconsistency in the data in that cell. For example, if you enter a date in a cell that is formatted as text, Excel will display a smart tag to let you know that the data may not be formatted correctly.

To get rid of the smart tag, you can either

1. click on it and select the appropriate option from the drop-down menu, or
2. you can change the data in the cell to resolve the issue that Excel has detected.

If you find the smart tags to be distracting, you can turn them off by going to the "File" tab, selecting "Options", and then choosing "Proofing" from the left-hand menu. Under "AutoCorrect Options", you can uncheck the box next to "Mark grammar errors as you type" and "Mark formatting inconsistencies as you type".