1 general "rule" that I read about a few years ago; if someone is sitting outside near their rv and their back is facing the road(this could be other campers as well), they don't usually want to be disturbed. If they are sitting facing the road, they are welcome to interaction.
The BOSS sometimes comes back from the laundry and tells me all about some lady she met while washing clothes. Of course, this is just generalized conversation but it sometimes can lead to getting information on places they have seen, parks they have stayed in, restaurants they have eaten at. Sometimes little tidbits of info can make/break your traveling experiences.
I'll say this since this person no longer frequents FRF. I posted to a thread a few years ago from a person looking for some info from an area we go to often. He thanked me by PM and we shared email addresses and we have been passing emails back and forth for 5 years and have even camped together twice. When we see each other, it's as if we have known each other for years and have only seen each other twice! He recently sold his Palamino and inherited a SOB MH. But by being cordial and helpful to the original post here on FRF, we have gained a great friendship.