Hierarchical attributes.. how are they used?

General talk
1

Let’s pick on the access=* key, it has several subsections in its hierarchy

To indicate that a route allows caravans, which of the following keys should I use?

access:vehicle:trailer:caravan=yes
vehicle:trailer:caravan=yes
trailer:caravan=yes
caravan=yes
access:caravan=yes

Some explanation in the wiki about how to use keys of this nature would be helpful, thanks!
cj

2

caravan=yes is the correct tag. The access wiki page already lists some Examples.