Help:Short words in searches

Changing minimum and maximum word lengths in MySQL
From MySQL's docs on Fine-Tuning MySQL Full-Text Search: The minimum and maximum length of words to be indexed is defined by the  and   system variables (available as of MySQL 4.0.0). See Section 5.3.3, “Server System Variables”. The default minimum value is four characters. The default maximum depends on your version of MySQL. If you change either value, you must rebuild your  indexes. For example, if you want three-character words to be searchable, you can set the  variable by putting the following lines in an option file: [mysqld] ft_min_word_len=3 Then restart the server and rebuild your  indexes. Also note particularly the remarks regarding myisamchk in the instructions following this list.