You can add prefix, suffix, superfix, and subfix text and supplementary information to a dimension value using the options in the Dimension Prefix dialog box. You can use this dialog box while you place or modify a dimension.
Click the dimension command you want to use, such as Smart Dimension or Dimension Between.
On the Dimension command bar, click Prefix 
.
In the Dimension Prefix dialog box, specify dimension text by doing any of the following:
Dimension Text—Type the text as you want it to appear in the Superfix, Prefix, Suffix, Subfix, and Subfix 2 boxes.
Annotation Symbol—Click a dimension text box and then click a symbol button on the dialog box to insert a symbol.
Property Text—Extract property text by copying and pasting a property text string, for example, %{Accuracy|GP}, or by typing the string directly into a box.
For more information and examples, see Dimension Prefix dialog box.
Click Apply or OK to save the dimension text and close the Dimension Prefix dialog box.
On the drawing, click to place the dimension.
The dimension text is displayed automatically with the dimension.
Tip:
Once you define the dimension text you want to use, you can continue to place dimensions using the same text, or you can open the Dimension Prefix dialog box and modify the text before placing the next dimension.
To control whether dimension text is placed with a dimension or not, use the Enable Prefix button 
on the Dimension command bar. When the Enable Prefix button is set, dimension text is added; when the button is cleared, dimension text is ignored.
You can use the Copy Attribute command to Copy a dimension prefix or style.
Select a dimension.
On the Dimension command bar, click Prefix .
In the Dimension Prefix dialog box, add or edit the content in the dimension prefix, suffix, superfix, subfix, or subfix 2 text.
For more information and examples, see Dimension Prefix dialog box.
Click Apply to change the dimension that you selected.