It seems that some people use the term "anti-Leibniz order" for what I'd call the "diagrammatic order" of composition: writing $f;g$ for the composition of $f$ and $g$ instead of $g\circ f$.
(I have no intention to discuss which order is "better"; I use both depending on context. Also, I believe the confusion is due to the fact that we forgot to mirror decimal numbers when we copied the concept from Arabic. For a reference to "anti-Leibniz", see https://ncatlab.org/nlab/show/anafunctor.)
Now, where does that terminology come from, and what does Leibniz have to do with it?