Use 'pencil in' to show the plan is not final and can change.

Temporarily Unsure

'Pencil in' is casual, more common in friendly or less formal business settings.

Casual Context

Use it for future events that you're planning but haven't fully committed to yet.

Use 'pencil in' when filling areas in a drawing with a pencil.

When adding subtle details, 'pencil in' indicates a gentle touch.

'Pencil in' is often used to describe the early stages of a creative work.