Coding of letters is based on the structure of the word. Logic of coding is very simple. Observe the word and the codes. It gives us following information:
If the word consists of four letters,
(i) and consonants occupy places at extreme ends only, then those consonants are replaced by [5] while vowels are replaced by either [20] (if both the vowels are same) or [15] (if both the vowels are different).
(ii) and the vowels occupy the second and the fourth places only then those vowels are replaced by [25], while the consonants are replaced by [5].
(iii) and the vowels occupy the first and third places only then those vowels are replaced by [30], while the consonants are replaced by [5].
If the word consists of three letters,
(i) and the vowels occupy places at extreme ends only then those vowels are replaced by [0], while the consonant is replaced by [5].
(ii) and the consonants occupy places at extreme ends only then those consonants are replaced by [5], while the vowel is replaced by [10].
Thus, in each and every case consonants are coded as [5] but numeric value assigned to vowels varies according to the position of vowels in a particular word.
