Working with PTC Mathcad Prime > Working with Math Expressions > Entering Math Expressions > Working with Labels > To Apply a Label
  
To Apply a Label
1. Select the math element that you want to label.
2. On the Math tab, in the Style group, click Labels.
3. Select one of the following labels:
Automatic
Variable
Unit
Constant
Function
System
Keyword
The selected label is applied to the math element.
4. To restore a math element’s automatically assigned label, in the Labels list, click Automatic.