I do thing that the list of linetype/subtypes could be improved. I wanted to have a 'presumed' <something> where 'presumed' wasn't a valid subtype for it. This seemed a bit arbitrary - why can I have a presumed wall but not a presumed rock-edge (Something like that - I forget exactly what it was). It seems to me that nearly everything could be 'presumed' or 'invisible', and also perhaps that some subtype should be main types. We could usefully review the list to see if it still makes sense.
Presumed = presumed. It means that I presume continuation but I don't know what's the type of continuation. Simply I presume that it is "wall". If you know that it is rock-border, why you need presumed rock-border? Lada -- ANONYMNI PRIPOJENI K INTERNETU - bez registrace, zdarma, ihned! Pripojeni na cisle 971 200 111 z cele CR, v Praze navic na cisle 971 200 555. Uzivatelske jmeno "post.cz", heslo "post.cz". http://www.post.cz