This category contains retail and wholesale sales occupations and customer and personal service occupations related to a wide range of industries, such as accommodation and food services, travel, tourism and cleaning services. Sales and service occupations can be linked, for the most part, to formal post-secondary or occupation-specific training programs. Others are characterized by periods of formal on-the-job training. Apprenticeship training is available for some specialized service occupations. Progression from sales and service occupations to positions of increased responsibility, or supervision, usually requires occupational experience and may require completion of related training programs.