The following are examples for suffix rules. Before each rule is a description of the rule. By convention, suffix rules usually come first in a thesaurus source file.
The term pony produces the alternative list pony, ponies, and ponies'.
+ y : y ies ies' ;
The following Greek suffixes do not get transformed.
+ us is ux ix : ;
Any of pit, pits, or pit's produces each of the other forms.
+ % s 's;
The previous rules do not include the suffixes s' or ies'. Since the standard character classes associated with the FTR word indexing rules cause a trailing apostrophe to be ignored for indexing purposes, a search for ponies retrieves ponies' and a search for ponies' retrieves ponies. The normal plural possessive suffixes need not be included.