I'd say trustworthiness, your friend is trusting you with keeping a secret that he or she will only share with you. I hope this helps :)
So it depends on what your planing on.
But a good well-developed plan should have a
Main - so what it’s about and what your researching about.
evidence- to back up your plan and your ideas
Point - what’s your point and your conclusion
paralanguage: <span>the nonlexical component of communication by speech, for example
intonation, pitch and speed of speaking, hesitation noises, gesture, and
facial expression.</span>
Hoped that help;)
- Whitewolf