In Ca. it means a loading zone for passengers or mail.
In Az. is means unrestricted parking unless otherwise posted.
"no parking"
Limited time parking.
Yellow painted curb means "no parking"
used for the loading and unloading of passengers or for mail deliveries by the post office.
you may not park next to a curb that is painted red.
Stopping or parking is not allowed (except buses).
parking
In Ca. it means a loading zone for passengers or mail. In Az. is means unrestricted parking unless otherwise posted.
just a curb
Yellow curbs generally imply that area is designated as a loading & unloading parking area.
If you mean the one by David Goodrich it was painted some time between 2000 and 2009.
You can never stop at a red curb. You can stop at a yellow curb but only to load or unload freight and/or passengers. You can not park in either of these zones.