(1) Specified disabilities are rated in one of two ways:

(a) Impairment due to amputation, total loss of hearing, and total loss of vision are rated according to RCW 51.32.080;

(b) Impairment for the loss of function of extremities, as well as partial loss of hearing or vision, is rated using a nationally recognized impairment rating guide unless otherwise precluded by department rule.

(2) Unspecified disabilities are rated in accordance with WAC 296-20-200 through 296-20-660.