Working With Model Items and Diagrams > Working with diagrams > Editing diagrams > Showing the alignment grid
  
Showing the alignment grid
The alignment grid helps you align items on a diagram. You can snap items to the grid.
To show the alignment grid
1. On the Tools menu, click Options.
2. Click the Diagrams entry.
3. Select the Show Alignment Grid check box.
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When working on a diagram, you can show or hide the alignment grid through the Show Grid command on the Diagram menu.