| IDFA | Identifier for Advertisers 
| Others |
| IDFA | Identifier for Advertising (iOS)
| Others |
| IDFA | Immune Deficiencies Foundation Australia
| Others |
| IDFA | Immune Deficiency Foundation of Australia
| Others |
| IDFA | Industrial Development Financing Authority
| Others |
| IDFA | Institute for Divorce Financial Analysts
| Others |
| IDFA | Internal Dairy Functions Association
| Others |
| IDFA | International Dairy Farmers Association
| Others |
| IDFA | International Dairy Food Act
| Others |
| IDFA | International Dairy Food Assumption
| Others |
| IDFA | International Dairy Foods Association
| Others |
| IDFA | International Documentary Film Festival Amsterdam
| Others |
| IDFA | International Documentary Filmfestival Amsterdam
| Others |
| IDFA | International Drug Free Athletics
| Others |