(a) General rule. An eligible applicant who, following an adversary adjudication has gained victory on the merits in the proceeding is a “prevailing party”. An eligible applicant may be a “prevailing party” if a settlement of the proceeding was effected on terms favorable to it or if the proceeding against it has been dismissed. In appropriate situations an applicant may also have prevailed if the outcome of the proceeding has substantially vindicated the applicant's position on the significant substantive matters at issue, even though the applicant has not totally avoided adverse final action.

(b) Segregation of costs. When a proceeding has presented a number of discrete substantive issues, an applicant may have prevailed even though all the issues were not resolved in its favor. If such an applicant is deemed to have prevailed, any award shall be based on the fees and expenses incurred in connection with the discrete significant substantive issue or issues on which the applicant's position has been upheld. If such segregation of costs is not practicable, the award may be based on a fair proration of those fees and expenses incurred in the entire proceeding which would be recoverable under § 308.175 if proration were not performed, whether separate or prorated treatment is appropriate, and the appropriate proration percentage, shall be determined on the facts of the particular case. Attention shall be given to the significance and nature of the respective issues and their separability and interrelationship.