The term "money order" has no particularized meaning in either Regulation CC or the UCC. The ability to stop payment depends on the characteristics of the specific item your bank sells; e.g. some of the checks banks sell that are labeled as money orders meet the definition of a cashiers check.
The words printed across the top have no legal significance.
_________________________
In this world you must be oh so smart or oh so pleasant. Well, for years I was smart. I recommend pleasant.