These are two settings unique to the Playground, found in the left side parameter panel. They are not required, but can be helpful in testing cases like Chat, where a pattern of back and forth conversation requires you to frequently retype the speakers' names.

In the Chat example, Inject Start Text is triggered when a user clicks “Submit”. A new line with the keyword “AI:” is automatically added to the prompt and the completion text begins generating.

Inject Restart Text is used so that the patterned conversation structure continues. At the end of the completion, a new line, with the keyword “Human:”, is automatically added to the end of the prompt. You can then begin typing your human response and continue the flow of conversation.