Ala. Code § 45-49-120.13: Promotions.

Vacancies in positions shall be filled by the appointing authority and, as far as practicable, the same shall be filled by promotion from among regular employees holding positions in the classified service, with the exception of the entry level classification for merit system laborers. These unskilled laborers who have been employed in such jurisdictions for a minimum of six months shall be entitled to take a promotional examination for entry into the merit system. Promotions shall be based upon merit, ability, and competency as may be provided in the rules.