Sort order within scenery.cfg

Since I need to re-install my old PC, I like to get everything for FS9 as properly done as possible this time.A question that I still cannot answer correctly enough is how the different scenery parts should be ordered priority-wise in scenery.cfg.I once read the level# defines the priority and not the area.xx number, and that landclass should have higher priority etc., but I'm quite unsure that my knowledge is right.So, what sort order is recommended for scenery.cfg (for instance "mesh first, then landclass, then all other scenery" or so) and what influence has the "priority" in the cfg file and what defines this priority (and, is level 1 more important than 12)?Andreas