On a search result tab, click Minimal
Pairs Options 
.
A drop-down box appears.
To specify which part of the search environment must be identical in each group, do one of the following:
Click Both Environments Identical.
Click Identical Preceding Environment.
Click Identical Following Environment.
To specify which characters in search environments can be ignored or must be identical in each group, do any of the following:
To ignore a type of character, click to select the check box
.All the characters in the area of the box are highlighted.
To require that a type of character be identical, click to clear the check box
.None of the characters in the area of the box are highlighted.
To include or exclude a character in an area of the box, click the character.
If a character is highlighted, it is ignored. If a character is not highlighted, it must be identical. If some, but not all, of the characters in an area are highlighted, the check box is selected, but dimmed
.