Dear Wanderer,
As-salamu alaykum
The verbal noun 'mann' comes from the main verb 'manna' which means in the main, to be gracious to or to show favour / generosity to.
As I stated as a clarification earlier in my post 'This can certainly include setting them free, but favours / grace can be conferred in a number of ways given the circumstances.'
With utmost respect, I simply cannot provide you every possible type of favour / amnesty / pardon that can be possibly granted given the numerous considerations / variables that a particular counsel of a state may proffer during peace time, in a particular situation, amongst different nations / people.
This is left to the states / leaders to best consider who to grant pardon / amnesty and how.
The main point of the verse is to safeguard the dignity, honour, respect and basic human rights of those captured whilst allowing for the vested interests of the state / powers in whose care the prisoners of war have fallen in to.
For example, the detaining state may consider to impose some obligations against certain elements of the detained for a period of time (given the risks they may impose) but still allowing them overarching freedoms in society with a view to allow them to become contributing members of the state whilst being recompensed financially and treated with justice. Hopefully, you will kindly see that I simply cannot cover every single scenario as it will almost mean that one attempts to rewrite a version akin to the Geneva Convention or arguably, beyond.
The verse is quite simple and I will provide my humble translation again.
"...Then either grant them a favour / show grace / be generous / gratuitous / reasonable (Arabic: mannan) or ransom (fidaan) them..." (47:4 - Part)
I hope this helps and that you kindly accept my response as the last to you on this matter.
Regards,
Joseph