What does H in 'Hind' and III refer to the enzyme 'Hind III'?

Explanation

(i) The first letter 'H' indicates the genus of the organism from which the enzyme was isolated. H=genus Haemophilus.
(ii) The fourth letter d indicates the particular strain used to produce the enzyme, d=strain Rd.
(iii) The Roman numerats denoted the sequence in which the restriction endonucleas e enzyme from that particular genus, species and strain of bacteria have been isolated iii i.e., third retriction endonuclease to be isolated from this species.