In this short note, we are interested in discussing characteristics of finite generating sets for $\mathcal{F}$, the set of all semiflows with non negative coefficients of a Petri Net. By systematically positioning these results over semi rings such as $\mathbb{N}$ or $\mathbb{Q^+}$ then over a field such as $\mathbb{Q}$, we were able to discover a handful of new results