Code snippets are stored in the 
  snippets.json file that is part of the AutoCAD AutoLISP Extension; you can add new or edit existing code snippets to improve your efficiency when writing AutoLISP programs. The 
  snippets.json file is written in JSON and supports C-style comments. Each code snippet should contain the following attributes: 
- name – A unique name for the code snippet; used if no description is provided 
  
- prefix – Defines the name to be typed and displayed in the IntelliSense list to insert the code snippet
  
- body – Expressions that define the code snippet, can contain new lines, tabs, and placeholders 
  
- description – Defines the text that should be displayed in the IntelliSense tooltip for the code snippet
  
The following shows the basic definition of a code snippet:
"ifprogn": 
  {
    "prefix": "ifp",
    "body":
      [
        "(if (${1:testexpr})",
            "\t(progn",
            "\t\t(${2:thenexpr})",
            "\t)",
        ")"
      ],
    "description": "if progn expression"
  }
-  In Visual Studio Code or another text editor, open the 
	 snippets.json file. 
	 Based on your OS, the 
		snippets.json file can be found in one of these locations: 
	  - Windows – 
		  %USERPROFILE%\.vscode\extensions\autodesk.autolispext-n.n.n\snippets 
		
- Mac OS – 
		  ~/.vscode/extensions/autodesk.autolispext-n.n.n/snippets 
		
 Note: n.n.n in the previous paths is a placeholder, the actual version of the AutoCAD AutoLISP Extension will vary over time as the extension is updated. 
	  
- In the 
	 snippets.json file, add your new code snippet or change an existing one. 
	 Note: Be careful about where you insert new text or which text you change, the formatting of the file is critical to it being properly parsed. 
	  
- Save the 
	 snippets.json file and test the code snippet changes.