If I understand your concern? All RV parks have varying limitations or restrictions.
i.e.
1. age restrictions "senior parks" min. 55 yrs. I think that the rational is old RV geezers tend to have more in common with other old Geezers in comparison to young RVers and most geezers prefer a more quiet ambient park atmosphere without teenagers:)
2. Some parks have a min. length of RV requirement i.e. 26ft.
3. Some parks don't allow truck campers or tent campers.
4. A general rule, the longer you stay the lower the daily rate. This is intended to help old RV geezers be able to afford a 4 to 6 month stay. Fixed income and all that.
5. Generally if you avoid "Resort" type RV parks, you won't find as many restrictions.
6. Even in areas that have "resort" type RV parks, if you look in your Good Sam RV Park Directory, you will find other RV parks that will meet your RV needs.
From an older Geezer:)