Informal upright is a peticular style, in it the tree grows in a curving matter like an S (no not the ugly mallsai), with a trunk that has obvious taper from the bottom to the top. Also branches come from the outside of each curve on the trunk starting at least 1/3 the way up the trunk.
This tree has none of this. It is straight as an arrow, with a Y split down low, and there's little taper if any. This tree does not fall under the informal upright style I MO.
Aaron