The AutoCAD dxf documentation shows a code 52 for linear dimensions that defines the oblique angle of the dimension lines, but this code is not recognized and not saved, it even does not allow to load files with this code.
I can work around this bug drawing it correctly but if the dimension is edited inside AutoCAD the information will be lost. You can test it yourself saving a linear dimension with an oblique angle as a dxf and loading it again.
And now a question for everybody. Would you like to be able to create this kind of dimensions even though you will loose this property if it is edited?