The IAB categories are an industry standard and are heavily used in services like advertising and Internet security and filtering appliances. There are 26 tier-1 (top level) categories, 366 tier-2 (sub level) categories, and an additional 12 tier-3 categories that are specific to the Webshrinker category service. The total number of categories are 404.
| QAG Category (Tier1 and Tier2) | OpenRTB Code |
| Arts & Entertainment | IAB1 |
| Books & Literature | IAB1-1 |
| Celebrity Fan/Gossip | IAB1-2 |
| Fine Art | IAB1-3 |
| Humor | IAB1-4 |
| Movies | IAB1-5 |
| Music | IAB1-6 |
| Television | IAB1-7 |
| Gambling/Casino | IAB1-8 |
| Lottery | IAB1-9 |
| Magazines | IAB1-10 |
| Concerts | IAB1-11 |
| Museums | IAB1-12 |
| Automotive | IAB2 |
| Auto Parts | IAB2-1 |
| Auto Repair | IAB2-2 |
| Buying/Selling Cars | IAB2-3 |
| Car Culture | IAB2-4 |
| Certified Pre-Owned | IAB2-5 |
| Convertible | IAB2-6 |
| Coupe | IAB2-7 |
| Crossover | IAB2-8 |
| Diesel | IAB2-9 |
| Electric Vehicle | IAB2-10 |
| Hatchback | IAB2-11 |
| Hybrid | IAB2-12 |
| Luxury | IAB2-13 |
| MiniVan | IAB2-14 |
| Mortorcycles | IAB2-15 |
| Off-Road Vehicles | IAB2-16 |
| Performance Vehicles | IAB2-17 |
| Pickup | IAB2-18 |
| Road-Side Assistance | IAB2-19 |
| Sedan | IAB2-20 |
| Trucks & Accessories | IAB2-21 |
| Vintage Cars | IAB2-22 |
| Wagon | IAB2-23 |
| Recreational Vehicles | IAB2-24 |
| Car Wash | IAB2-25 |
| Business | IAB3 |
| Advertising | IAB3-1 |
| Agriculture | IAB3-2 |
| Biotech/Biomedical | IAB3-3 |
| Business Software | IAB3-4 |
| Construction | IAB3-5 |
| Forestry | IAB3-6 |
| Government | IAB3-7 |
| Green Solutions | IAB3-8 |
| Human Resources | IAB3-9 |
| Logistics | IAB3-10 |
| Marketing | IAB3-11 |
| Metals | IAB3-12 |
| Cable Companies | IAB3-13 |
| Internet/Broadband | IAB3-14 |
| Phone/Services | IAB3-15 |
| Storage Facilities | IAB3-16 |
| Transportation | IAB3-17 |
| Conference/Events/Seminars | IAB3-18 |
| Convenience / Gas | IAB3-19 |
| Laundry / dry cleaning | IAB3-20 |
| Mortuaries | IAB3-21 |
| Utility Companies | IAB3-22 |
| Equipment Rentals | IAB3-23 |
| Record Labels | IAB3-24 |
| Attorney | IAB3-25 |
| Careers | IAB4 |
| Career Planning | IAB4-1 |
| College | IAB4-2 |
| Financial Aid | IAB4-3 |
| Job Fairs | IAB4-4 |
| Job Search | IAB4-5 |
| Resume Writing/Advice | IAB4-6 |
| Nursing | IAB4-7 |
| Scholarships | IAB4-8 |
| Telecommuting | IAB4-9 |
| U.S. Military | IAB4-10 |
| Career Advice | IAB4-11 |
| Employment Agencies | IAB4-12 |
| Education | IAB5 |
| 7-12 Education | IAB5-1 |
| Adult Education | IAB5-2 |
| Art History | IAB5-3 |
| Colledge Administration | IAB5-4 |
| College Life | IAB5-5 |
| Distance Learning | IAB5-6 |
| English as a 2nd Language | IAB5-7 |
| Language Learning | IAB5-8 |
| Graduate School | IAB5-9 |
| Homeschooling | IAB5-10 |
| Homework/Study Tips | IAB5-11 |
| K-6 Educators | IAB5-12 |
| Private School | IAB5-13 |
| Special Education | IAB5-14 |
| Studying Business | IAB5-15 |
| Family & Parenting | IAB6 |
| Adoption | IAB6-1 |
| Babies & Toddlers | IAB6-2 |
| Daycare/Pre School | IAB6-3 |
| Family Internet | IAB6-4 |
| Parenting - K-6 Kids | IAB6-5 |
| Parenting teens | IAB6-6 |
| Pregnancy | IAB6-7 |
| Special Needs Kids | IAB6-8 |
| Eldercare | IAB6-9 |
| Health & Fitness | IAB7 |
| Exercise | IAB7-1 |
| A.D.D. | IAB7-2 |
| AIDS/HIV | IAB7-3 |
| Allergies | IAB7-4 |
| Alternative Medicine | IAB7-5 |
| Arthritis | IAB7-6 |
| Asthma | IAB7-7 |
| Autism/PDD | IAB7-8 |
| Bipolar Disorder | IAB7-9 |
| Brain Tumor | IAB7-10 |
| Cancer | IAB7-11 |
| Cholesterol | IAB7-12 |
| Chronic Fatigue Syndrome | IAB7-13 |
| Chronic Pain | IAB7-14 |
| Cold & Flu | IAB7-15 |
| Deafness | IAB7-16 |
| Dental Care | IAB7-17 |
| Depression | IAB7-18 |
| Dermatology | IAB7-19 |
| Diabetes | IAB7-20 |
| Epilepsy | IAB7-21 |
| GERD/Acid Reflux | IAB7-22 |
| Headaches/Migraines | IAB7-23 |
| Heart Disease | IAB7-24 |
| Herbs for Health | IAB7-25 |
| Holistic Healing | IAB7-26 |
| IBS/Crohn's Disease | IAB7-27 |
| Incest/Abuse Support | IAB7-28 |
| Incontinence | IAB7-29 |
| Infertility | IAB7-30 |
| Men's Health | IAB7-31 |
| Nutrition | IAB7-32 |
| Orthopedics | IAB7-33 |
| Panic/Anxiety Disorders | IAB7-34 |
| Pediatrics | IAB7-35 |
| Physical Therapy | IAB7-36 |
| Psychology/Psychiatry | IAB7-37 |
| Senor Health | IAB7-38 |
| Sexuality | IAB7-39 |
| Sleep Disorders | IAB7-40 |
| Smoking Cessation | IAB7-41 |
| Substance Abuse | IAB7-42 |
| Thyroid Disease | IAB7-43 |
| Weight Loss | IAB7-44 |
| Women's Health | IAB7-45 |
| Cosmetic Surgery | IAB7-46 |
| Laser Eye Care | IAB7-47 |
| Optical/Eye Care | IAB7-48 |
| Physicians / Physician Services | IAB7-49 |
| Vitamins / Supplements | IAB7-50 |
| Pharmacy | IAB7-51 |
| Hospitals | IAB7-52 |
| Clinical Research | IAB7-53 |
| Chiropractic | IAB7-54 |
| Food & Drink | IAB8 |
| American Cuisine | IAB8-1 |
| Barbecues & Grilling | IAB8-2 |
| Cajun/Creole | IAB8-3 |
| Chinese Cuisine | IAB8-4 |
| Cocktails/Beer | IAB8-5 |
| Coffee/Tea | IAB8-6 |
| Cuisine-Specific | IAB8-7 |
| Desserts & Baking | IAB8-8 |
| Dining Out | IAB8-9 |
| Food Allergies | IAB8-10 |
| French Cuisine | IAB8-11 |
| Health/Lowfat Cooking | IAB8-12 |
| Italian Cuisine | IAB8-13 |
| Japanese Cuisine | IAB8-14 |
| Mexican Cuisine | IAB8-15 |
| Vegan | IAB8-16 |
| Vegetarian | IAB8-17 |
| Wine | IAB8-18 |
| Beverages | IAB8-19 |
| Catering | IAB8-20 |
| Fast Food | IAB8-21 |
| Pizza | IAB8-22 |
| Night Clubs/Bars | IAB8-23 |
| Hobbies & Interests | IAB9 |
| Art/Technology | IAB9-1 |
| Arts & Crafts | IAB9-2 |
| Beadwork | IAB9-3 |
| Birdwatching | IAB9-4 |
| Board Games/Puzzles | IAB9-5 |
| Candle & Soap Making | IAB9-6 |
| Card Games | IAB9-7 |
| Chess | IAB9-8 |
| Cigars | IAB9-9 |
| Collecting | IAB9-10 |
| Comic Books | IAB9-11 |
| Drawing/Sketching | IAB9-12 |
| Freelance Writing | IAB9-13 |
| Genealogy | IAB9-14 |
| Getting Published | IAB9-15 |
| Guitar | IAB9-16 |
| Home Recording | IAB9-17 |
| Investors & Patents | IAB9-18 |
| Jewelry Making | IAB9-19 |
| Magic & Illusion | IAB9-20 |
| Needlework | IAB9-21 |
| Painting | IAB9-22 |
| Photography | IAB9-23 |
| Radio | IAB9-24 |
| Roleplaying Games | IAB9-25 |
| Sci-Fi & Fantasy | IAB9-26 |
| Scrapbooking | IAB9-27 |
| Screenwriting | IAB9-28 |
| Stamps & Coins | IAB9-29 |
| Video & Computer Games | IAB9-30 |
| Woodworking | IAB9-31 |
| Fire Arms/Gun Shows | IAB9-32 |
| Home & Garden | IAB10 |
| Appliances | IAB10-1 |
| Entertaining | IAB10-2 |
| Environmental Safety | IAB10-3 |
| Gardening | IAB10-4 |
| Home Repair | IAB10-5 |
| Home Theater | IAB10-6 |
| Interior Decorating | IAB10-7 |
| Landscaping | IAB10-8 |
| Remodeling & Construction | IAB10-9 |
| Furniture Outdoor | IAB10-10 |
| Pool Supplies | IAB10-11 |
| Security Systems | IAB10-12 |
| Windows | IAB10-13 |
| HVAC | IAB10-14 |
| Pest Control/Bug Extermination | IAB10-15 |
| Hot Tubs / Spas | IAB10-16 |
| Home Utilities | IAB10-17 |
| Flooring / Carpet / Rug | IAB10-18 |
| Cleaning Services | IAB10-19 |
| Household Cleaners | IAB10-20 |
| Appliance Repair | IAB10-21 |
| Plumbing | IAB10-22 |
| Matress | IAB10-23 |
| Law, Gov't & Politics | IAB11 |
| Immigration | IAB11-1 |
| Legal Issues | IAB11-2 |
| U.S. Government Resources | IAB11-3 |
| Politics | IAB11-4 |
| Commentary | IAB11-5 |
| Civic Organizations | IAB11-6 |
| Non Profit | IAB11-7 |
| Ecology | IAB11-8 |
| News | IAB12 |
| International News | IAB12-1 |
| National News | IAB12-2 |
| Local News | IAB12-3 |
| Newspapers | IAB12-4 |
| Personal Finance | IAB13 |
| Beginning Investing | IAB13-1 |
| Credit/Debt & Loans | IAB13-2 |
| Financial News | IAB13-3 |
| Financial Planning | IAB13-4 |
| Hedge Fund | IAB13-5 |
| Insurance | IAB13-6 |
| Investing | IAB13-7 |
| Mutual Funds | IAB13-8 |
| Options | IAB13-9 |
| Retirement Planning | IAB13-10 |
| Stocks | IAB13-11 |
| Tax Planning | IAB13-12 |
| Banks | IAB13-13 |
| Society | IAB14 |
| Dating | IAB14-1 |
| Divorce Support | IAB14-2 |
| Gay Life | IAB14-3 |
| Marriage | IAB14-4 |
| Senior Living | IAB14-5 |
| Teens | IAB14-6 |
| Weddings | IAB14-7 |
| Ethnic Specific | IAB14-8 |
| Cemetary/Memorial | IAB14-9 |
| Donation/Charity | IAB14-10 |
| Science | IAB15 |
| Astrology | IAB15-1 |
| Biology | IAB15-2 |
| Chemistry | IAB15-3 |
| Geology | IAB15-4 |
| Paranormal Phenomena | IAB15-5 |
| Physics | IAB15-6 |
| Space/Astronomy | IAB15-7 |
| Geography | IAB15-8 |
| Botany | IAB15-9 |
| Weather | IAB15-10 |
| Pets | IAB16 |
| Aquariums | IAB16-1 |
| Birds | IAB16-2 |
| Cats | IAB16-3 |
| Dogs | IAB16-4 |
| Large Animals | IAB16-5 |
| Reptiles | IAB16-6 |
| Veterinary Medicine | IAB16-7 |
| Sports | IAB17 |
| Auto Racing | IAB17-1 |
| Baseball | IAB17-2 |
| Bicycling | IAB17-3 |
| Bodybuilding | IAB17-4 |
| Boxing | IAB17-5 |
| Canoeing/Kayaking | IAB17-6 |
| Cheerleading | IAB17-7 |
| Climbing | IAB17-8 |
| Cricket | IAB17-9 |
| Figure Skating | IAB17-10 |
| Fly Fishing | IAB17-11 |
| Football | IAB17-12 |
| Freshwater Fishing | IAB17-13 |
| Game & Fish | IAB17-14 |
| Golf | IAB17-15 |
| Horse Racing | IAB17-16 |
| Horses | IAB17-17 |
| Hunting/Shooting | IAB17-18 |
| Inline Skating | IAB17-19 |
| Martial Arts | IAB17-20 |
| Mountain Biking | IAB17-21 |
| NASCAR Racing | IAB17-22 |
| Olympics | IAB17-23 |
| Paintball | IAB17-24 |
| Power & Motorcycles | IAB17-25 |
| Pro Basketball | IAB17-26 |
| Pro Ice Hockey | IAB17-27 |
| Rodeo | IAB17-28 |
| Rugby | IAB17-29 |
| Running/Jogging | IAB17-30 |
| Sailing | IAB17-31 |
| Saltwater Fishing | IAB17-32 |
| Scuba Diving | IAB17-33 |
| Skateboarding | IAB17-34 |
| Skiing | IAB17-35 |
| Snowboarding | IAB17-36 |
| Surfing/Bodyboarding | IAB17-37 |
| Swimming | IAB17-38 |
| Table Tennis/Ping-Pong | IAB17-39 |
| Tennis | IAB17-40 |
| Volleyball | IAB17-41 |
| Walking | IAB17-42 |
| Waterski/Wakeboard | IAB17-43 |
| World Soccer | IAB17-44 |
| Fitness | IAB17-45 |
| Style & Fashion | IAB18 |
| Beauty | IAB18-1 |
| Body Art | IAB18-2 |
| Fashion | IAB18-3 |
| Jewelry | IAB18-4 |
| Clothing | IAB18-5 |
| Accessories | IAB18-6 |
| Shoes/Boots | IAB18-7 |
| Hair Loss | IAB18-8 |
| Tanning | IAB18-9 |
| Technology & Computing | IAB19 |
| 3-D Graphics | IAB19-1 |
| Animation | IAB19-2 |
| Antivirus Software | IAB19-3 |
| C/C++ | IAB19-4 |
| Cameras & Camcorders | IAB19-5 |
| Cell Phones | IAB19-6 |
| Computer Certification | IAB19-7 |
| Computer Networking | IAB19-8 |
| Computer Peripherals | IAB19-9 |
| Computer Reviews | IAB19-10 |
| Data Centers | IAB19-11 |
| Databases | IAB19-12 |
| Desktop Publishing | IAB19-13 |
| Desktop Video | IAB19-14 |
| IAB19-15 | |
| Graphics Software | IAB19-16 |
| Home Video/DVD | IAB19-17 |
| Internet Technology | IAB19-18 |
| Java | IAB19-19 |
| JavaScript | IAB19-20 |
| Mac Support | IAB19-21 |
| MP3/MIDI | IAB19-22 |
| Net Conferencing | IAB19-23 |
| Net for Beginners | IAB19-24 |
| Network Security | IAB19-25 |
| Palmtops/PDAs | IAB19-26 |
| PC Support | IAB19-27 |
| Portable | IAB19-28 |
| Entertainment | IAB19-29 |
| Shareware/Freeware | IAB19-30 |
| Unix | IAB19-31 |
| Visual Basic | IAB19-32 |
| Web Clip Art | IAB19-33 |
| Web Design/HTML | IAB19-34 |
| Web Search | IAB19-35 |
| Windows | IAB19-36 |
| Computers | IAB19-37 |
| Stereo/TV | IAB19-38 |
| Other Software | IAB19-39 |
| Travel | IAB20 |
| Adventure Travel | IAB20-1 |
| Africa | IAB20-2 |
| Air Travel | IAB20-3 |
| Australia & New Zealand | IAB20-4 |
| Bed & Breakfasts | IAB20-5 |
| Budget Travel | IAB20-6 |
| Business Travel | IAB20-7 |
| By US Locale | IAB20-8 |
| Camping | IAB20-9 |
| Canada | IAB20-10 |
| Caribbean | IAB20-11 |
| Cruises | IAB20-12 |
| Eastern Europe | IAB20-13 |
| Europe | IAB20-14 |
| France | IAB20-15 |
| Greece | IAB20-16 |
| Honeymoons/Getaways | IAB20-17 |
| Hotels | IAB20-18 |
| Italy | IAB20-19 |
| Japan | IAB20-20 |
| Mexico & Central America | IAB20-21 |
| National Parks | IAB20-22 |
| South America | IAB20-23 |
| Spas | IAB20-24 |
| Theme Parks | IAB20-25 |
| Traveling with Kids | IAB20-26 |
| United Kingdom | IAB20-27 |
| Real Estate | IAB21 |
| Apartments | IAB21-1 |
| Architects | IAB21-2 |
| Buying/Selling Homes | IAB21-3 |
| Timeshare | IAB21-4 |
| Shopping | IAB22 |
| Contests & Freebies | IAB22-1 |
| Couponing | IAB22-2 |
| Comparison | IAB22-3 |
| Engines | IAB22-4 |
| Auctions | IAB22-5 |
| Cellular Stores | IAB22-6 |
| Grocery Stores | IAB22-7 |
| Malls | IAB22-8 |
| Department Store | IAB22-9 |
| Fairs/Farmers Markets | IAB22-10 |
| Antiques | IAB22-11 |
| Office supplies | IAB22-12 |
| Pawnshop | IAB22-13 |
| Music Stores | IAB22-14 |
| Toys | IAB22-15 |
| Fireworks | IAB22-16 |
| Florist/Balloons | IAB22-17 |
| Religion & Spirituality | IAB23 |
| Alternative Religions | IAB23-1 |
| Atheism/Agnosticism | IAB23-2 |
| Buddhism | IAB23-3 |
| Catholicism | IAB23-4 |
| Christianity | IAB23-5 |
| Hinduism | IAB23-6 |
| Islam | IAB23-7 |
| Judaism | IAB23-8 |
| Latter-Day Saints | IAB23-9 |
| Pagan/Wiccan | IAB23-10 |
| Psychics | IAB23-11 |
| Uncategorized | IAB24 |
| Non-Standard Content | IAB25 |
| Unmoderated UGC | IAB25-1 |
| Extreme Graphic/Explicit Violence | IAB25-2 |
| Pornography | IAB25-3 |
| Profane Content | IAB25-4 |
| Hate Content | IAB25-5 |
| Under Construction | IAB25-6 |
| Incentivized | IAB25-7 |
| Illegal Content | IAB26 |
| Illegal Content | IAB26-1 |
| Warez | IAB26-2 |
| Spyware/Malware | IAB26-3 |
| Copyright Infringement | IAB26-4 |
Reference: https://www.iab.com/wp-content/uploads/2015/06/DAASTAdCategories.xlsx