(a) The Dictionary of Occupational Titles includes information about jobs (classified by their exertional and skill requirements) that exist in the national economy. Appendix 2 of this part provides rules using this data reflecting major functional and vocational patterns.

(b) The Board applies that rules in appendix 2 of this part in cases where a claimant is not doing substantial gainful activity and is prevented by a severe impairment(s) from doing vocationally relevant past work.

(c) The rules in appendix 2 of this part do not cover all possible variations of factors. The Board does not apply these rules if one of the findings of fact about the claimant's vocational factors and residual functional capacity is not the same as the corresponding criterion of a rule. In these instances, the Board gives full consideration to all relevant facts in accordance with the definitions and discussions under vocational considerations. However, if the findings of fact made about all factors are the same as the rule, the Board uses that rule to decide whether that claimant is disabled.