For central route processing to occur, your message must be compatible with your audience's cognitive capacities. If a person lacks the mental capacity to understand your message, they will be unable to critically assess it and will almost certainly process it through the peripheral route. For example, if a four-year-old child receives a political message from an adult, they will not be able to evaluate its content carefully enough to make an informed decision about whether or not to trust it. The child can only follow the instructions given in the message or the voice cues from the speaker. Any additional information that could help them make an educated choice is lost to them. Your message must also reach the intended recipient. If you send a message to an address that does not exist, it will be discarded by the network before it reaches its destination. Similarly, if an address belongs to someone who has not received your message, they will not receive it. As long as there are other addresses available, yours will be delivered via one of the other routes. At a minimum, therefore, a message needs to contain enough information for someone to identify its destination. It may also need to include more specific details for effective delivery - such as through private communication channels - but even then there is no guarantee that it will be received. In addition to these basic requirements, central route messages tend to be more formal, while peripheral route messages are less structured.