Any specific requirements for service hours?

Are there any specific requirements for what constitutes service hours?

Do they have to be performed in conjunction with or benefitting an established organization like 501c3 or a municipality?

Can they be performed for an individual in extreme need, like for example a disabled person who needs help with yardwork for getting their house on the market or something like that?

Edited to add:

I'm familiar with the hours of service requirements for each rank and conservation hours for life rank. Just wondering if there is a guideline for what's appropriate/allowed. Thanks