How to list proposals I assisted in writing on CV In the case a Post-doc is not allowed to be a Co-PI on proposals submitted to NSF etc. i.e., some schools require PIs to add a "mentoring plan" for post-docs (for budgeting purposes). In the event the post-doc developed the idea and helped in writing the proposal, how does the post-doc list this in his academic CV?
1) A great tip is to look at other successful people who have the same experience and see how or whether they listed that on their CV. If you know any postdocs in recent history with the same experience, look at their website or ask to see their CV as a template.

2) If your only contribution to the grant is that you developed your own Postdoc mentoring program, I'm not sure that I'd consider that grant writing experience. But, I don't really know- that's just my gut feeling.

3) Later in your career you would probably not list grant activity that you are not the PI or Co-PI for. For a postdoc or grad student you want to make it clear that you worked on grant writing but you're not an investigator. 

You could have a section that looks something like:

Grant Activity - neither PI or Co-PI

Summary of contributions. (NSF Grant Number). Grant Title. $Award Amount. Date.

For example:

Grant Activity - neither PI or Co-PI

Editor, figure designer, and wrote mentoring plan. (NSF 123456789). Investigating Greatness by Posting on Stack Exchange. Awarded $300,000. 2017