| ISTR | It Stands To Reason | 它代表理性 |
| ISTR | Information Security and Testing Research | 信息安全与测试研究 |
| ISTR | I Seem To Recall | 我似乎回忆起来了 |
| ISTR | Institute of Safety in Technology and Research (UK) | 技术与研究安全研究所（英国） |
| ISTR | Interoperability Standards Technical Reports | 互操作性标准技术报告 |
| ISTR | Institute for Science Training and Research | 科学训练研究所 |
| ISTR | International Society for Third-Sector Research | 国际第三部门研究学会 |
| ISTR | Internet Security Threat Report (Symantec) | Internet安全威胁报告（Symantec） |
| ISTR | I Seem to Remember | 我似乎还记得 |