I have tried searching here and google, went in about 10 pages in the results before giving up and just asking here. I am trying to add new map marker types so that I can have a custom icon appear on the map for certain locations in my mod, changing icons of current ones aren't an option so I just want to know how to add more.

I have looked through the content browser about a dozen times now trying to find any sign of them and everywhere else I could think of too so any help with this would be great.

Don't think it's possible.

Surely it isn't hard coded for something that should be so simple

i often read that it is

Damn, well I guess I will have to stick with retexturing the couple of un-used icons unless another way is found.

are there any? How do you use them?

Castle Dour
Mine
Jarls Longhouse
Runestone
Temple

They are all the ones that aren't used by any map markers according to UESP, not sure about Castle Dour's one but the others I have only ever seen used in mods. The Moonpath to Elswyr mod uses the Runestone marker to show the location of the path for instance. Five markers isn't near enough for my mod as I will need more for unique cities and such but I can make do with what there is, it still won't look very good using icons which clearly are not meant for the location though.

Edit: Oh and they are in the same list as the rest of the markers when editing the map marker object.

Thank you..

But how can I use them in the CK? ( I have the same limitation as you have..)

Well using them is the same as any other type of map marker, changing the image on the other hand is not done in the CK as far as I know otherwise it would be simple to add another one (so much for Bethesda's total mod support, not the first thing that is hard wired that could have not been). I haven't looked too much into that side of it yet, wanted to see if there was a way to add new ones than have to change vanilla ones first.

Ah, I never noticed that those are not used by the Vanilla Game