  We investigate the group gradings on the algebra of upper triangular matrices
over an arbitrary field, viewed as a Lie algebra. These results were obtained a
few years early by the same authors. We provide streamlined proofs, and present
a complete classification of isomorphism classes of the gradings. We also
provide a classification of the practical isomorphism classes of the gradings,
which is a better alternative way to consider these gradings up to being
essentially the same object. Finally, we investigate in details the case where
the characteristic of the base field is $2$, a topic that was neglected in
previous works.
