Append important information to every user message (option)

As title says, create an option to append a set text message to each user message when it is sent. This would be useful to place emphasis on specific important information that the LLM should always be paying attention to, as due to how LLMs work, more recent text is focused on more than older text. I already manually use this technique to keep mission critical information and instructions in constant context and fresh in the "memory" of the LLM.