Lynne wrote:

If you report the departing traffic in sight, you can maintain visual
separation,

No. Visual separation is never used to reduce runway separation.


and the controller can use non-standard separation.

Just what might that be?


Another
option is the controller can have you both (or all) in sight, and he
can provide instructions to you to avoid a conflict.

You are thinking of separation that may be required of airborne
aircraft. He was asking about runway separation.