Better term for undefined geometry

Hi all,

I am trying to render topographic map in my local PC, and need you advise about specific English term for “undefined/undefinable” geometries.

Sometimes the geometry of the object cannot be defined at all, e.g. transition zone for shallow waters, hidden in reeds. There is no specific line, separating land from water. It is mapped as dash line on topo maps, and it is different from mapping intermittent waters or shorelines.

Another example, water reservoirs on their shallowest side. You will see it full of water on spring and wet mud on dry season. Users start re-mapping it every time the satellite imagery updates, while normal topo map will mark it with “undefinable” and the problem solved.

Last example, transition from woodland to shrub land to grassland are not always clearly distinguished one from another. It is not intermittent nor seasonal, it is simply not possible to define.

Thus I need your advise what word is better to use
undefinable = yes
geometry:accuracy = undefinable
geometry:accuracy = undefined

IMO the latter is worse as one may think that geometry need adjustment.

PS: writing this post already let me sorting things in my head, but maybe some of you happen to know such terms in Western topography practice. Thank you in advance.

Found Swiss topo symbols and they use “undefined outline”

Found accuracy=*

It is probably part of some import; values are not limited with numbers (both in meters and feet) and include some special words:


I think not a big deal if I add accuracy=undefined for my purposes; when proposal starts there will be some statistics of tag use.