4.2 Russell Soundex rules.   The Russell Soundex system is a name code using a very simple set of rewrite rules. These are set out in the following table:

1.	change the vowel letters [a, e, i, o, u] to “0”
2.	omit the semi-vowel letters [h, y, w]
3.	reduce doubled letters to single ones
4.	remember the initial letter
5.	change the consonant letters to digits as follows:
	a.  change b, f, p, and v to “1” b.  change c, g, j, k, q, s, x, and z to “2” c.  change d, and t to “3” d.  change l to “4” e.  change m, and n to “5” f.  change r to “6”
6.	delete second digit if it is the same as the first
7.	change the first digit back to the remembered letter of step 4
8.	delete all digits that are the same as the one next preceding
9.	delete all 0’s
10.	supply up to three digits by adding 0’s
11.	truncate to three digits by deleting the extra digits

Here are some examples of soundex codes with the effects of certain rules noted: