| Satellite Communications | 775 |
| Satellite Dishes-Television | 775 |
| Satellite Equipment & Systems | 776 |
| Sauna Equipment & Supplies | 776 |
| Sausages | 776 |
| Savings & Loan Associations | 776 |
| Sawmills | 776 |
| Saws | 776 |
| Saws-Renting | 776 |
| Saws-Sharpening & Repairing | 776 |
| Scaffolding & Aerial Lifts | 776 |
| Scales | 776 |
| Scales-Renting | 776 |
| Scales-Repairing | 777 |
| Scanning Services & Equipment | 777 |
| School Development Programs | 777 |
| School Furniture & Equipment | 777 |
| School Information | 777 |
| School Supplies | 777 |
| School Uniforms | 777 |
| Schools-Academic-Colleges & Universities | 779 |
| Schools-Academic-Preschool & Kindergartens | 782 |
| Schools-Academic-Secondary & Elementary | 784 |
| Schools-Academic-Special Education | 786 |
| Schools-Business & Vocational | 787 |
| Schools-General Interest | 792 |
| Schools-Industrial & Technical & Trade | 792 |
| Schools-Medical & Dental Assistants & | 793 |
| Technicians |
| Schools-Parochial-Academic | 793 |
| Schools-Private | 793 |
| Schools-Religious Education | 794 |
| Scientific Apparatus & Instruments | 794 |
| Scrap Metals | 794 |
| Scrapbooks-Supplies, Service & Instruction | 794 |
| Screen Enclosures | 794 |
| Screen Printing | 794 |
| Screening & Sifting Equipment | 795 |
| Screens | 795 |
| Screws | 795 |
| Sculptors | 795 |
| Seafood | 796 |
| Seafood-Whsle | 797 |
| Sealcoating | 797 |
| Seals-Notary & Corporation | 797 |
| Seals-Oil, Grease, Etc | 797 |
| Searchlights & Floodlights | 797 |
| Secondhand Stores | 797 |
| Secretarial Services | 797 |
| Security Consultants | 797 |
| Security Control Equipment, Systems & | 798 |
| Monitoring |
| Security Control Equipment Systems & | 799 |
| Monitoring-Whsle |
| Security Guard & Patrol Service | 799 |
| Security Systems & Consultants | 800 |
| Security Systems-Communications & Computer | 800 |
| Seeds & Bulbs | 800 |
| Self-Defense | 800 |
| Seminaries | 800 |
| Senior Citizens’ Services | 800 |
| Septic Tanks & Systems-Cleaning | 801 |
| Septic Tanks & Systems-Contractors & Dealers | 801 |
| Septic Tanks & Systems-Whsle & Mfrs | 802 |
| Service Station Equipment & Supplies | 802 |
| Service Stations-Gasoline & Oil | 802 |
| Sewage Disposal Systems | 803 |
| Sewage Treatment Equipment | 803 |
| Sewage Treatment Equipment- Service & Repair | 803 |