This guideline API RP 13L:2024 is structured into two distinct sections. The opening section outlines foundational competencies and expertise required for personnel—including employees and contractors—to qualify as specialists in drilling and completion fluids. It encompasses essential techniques typically addressed in introductory training programs for drilling fluid operations. The subsequent section details advanced proficiencies necessary for managing intricate well operations on-site. While general proficiency expectations for both fundamental and specialized skills are highlighted, comprehensive definitions of mastery levels remain intentionally flexible to accommodate operational diversity.