(iv) Reasonable allocation. The allocation of residual shared employees under the small group method provided for in this paragraph (c)(5) must be reasonable. Reasonable allocations generally include allocations that are based on the level of services that the residual shared employees provide to the employer's qualified separate lines of business, the similar treatment of similarly situated residual shared employees, and other bona fide business criteria; in contrast, an allocation that is designed to maximize benefits for select employees is not considered a reasonable allocation. For example, allocation of all residual shared employees who work in the same department, or at the same location, to the same qualified separate line of business would be an indication of reasonableness. However, allocation of a group of similarly situated residual shared employees to a qualified separate line of business for which they provide minimal services might not be considered reasonable. In addition, the allocation of the professional employees of a department to one qualified separate line of business and the allocation of the support staff of the same department to a different qualified separate line of business would not be reasonable.