*Question E1F09:
[FCC Part 97.113(a)(4)] Which of the following cannot be transmitted over an amateur radio mesh network?*  

*Correct Answer is  C: Messages encoded to obscure their meaning*  

### AI Response: (may contain errors)  

In the context of amateur radio operations, the FCC has specific rules about what can and cannot be transmitted. Let's break down the choices:

1. **Correct Answer: Messages encoded to obscure their meaning**

   - **Explanation**: According to FCC Part 97.113(a)(4), amateur radio operators are prohibited from transmitting messages encoded for the purpose of obscuring their meaning. This rule is in place to ensure transparency and prevent the use of amateur radio for clandestine communications. The only exceptions are for control signals of space stations or radio control craft.

2. **Why the other choices are incorrect**:

   - **Third party traffic**: This refers to messages sent on behalf of someone who is not a licensed amateur radio operator. While there are restrictions and conditions under which third party traffic can be transmitted, it is not outright prohibited. Therefore, this choice is incorrect as something that "cannot be transmitted."

   - **Email**: Sending email over an amateur radio mesh network is permissible, provided it adheres to the rules and regulations, such as not being encoded to obscure its meaning. Thus, this choice is also incorrect as something that "cannot be transmitted."

3. **Useful Rule of Thumb**:

   - **Transparency**: Always ensure that communications over amateur radio are open and not encrypted or encoded to hide their meaning, except in specific allowed cases. This maintains the spirit of amateur radio as a hobby for learning and public service.