Each soldier you build can be Prestiged once only.
By the time you prestige this soldier all perks are unlocked as part of the normal process of achieving prestige for this soldier.
Weapons, lethals, tactical, streaks can only be unlocked for this soldier with squad point. You have earned.
Once this soldier is prestiged, all unlocks remain unlocked.
Prestiging this solider unlocks a prestige icon and present back ground that can be used by all soldiers you may have created.
To prestige again set up a new soldier.
Rinse and repeat.
Once you prestige a second soldier this unlocks a new prestige icon. Back ground that can be used by all soldiers.
And so on......