Dear Amol,
What exactly is the issue? What is the meaning of the sentence "I want to make a list of rules for sending to the people with resignation acknowledgement." The sentence is little clumsy, can you please simplify it? Secondly, heading of your post is "Rule for Notice Period". But in the main body, you have given emphasis on post-separation behaviour. Therefore, what you want exactly?
Though provisions of employee separation are made in the appointment letter itself, well-organised companies design a separate policy on employee separation. In this policy entire process is outline once the resignation received till the Full and Final Settlement (FFS) is made. You may do so to bring clarity of the separation process.
Portion of the last sentence reads "not to spread negativity about organisation." Why you are anxious about employee talking negative? Why you (I mean leadership of your organisation) are fraught with queasiness? If somebody were to talk negative, they will do it anyway. How can you stop it after employee's exit or even monitor it?
If the company's brand image is strong, if the systems and processes are well-defined, if the company has value-based administration, if the leadership promotes impeccable moral soundness then why anyone should worry?
No company has stopped growing or stopped getting good candidates because of the 1-2 negative incidents. Take the case of fiasco that
HR had made in Tech Mahindra while removing one of the employees. Notwithstanding apology arising out of shoddy handling of the employee removal, Tech Mahindra is growing and continues to attract quality manpower. Therefore, ignore about bad publicity by ex-employees unless your company is really involved in shady activities!
Thanks,
Dinesh Divekar