seems you like to turn this issue to an academic exercise or an attempt to display knowledge when you actually know what people are trying to say. I’m from Nigeria and majority of the people here refer to the process of affixing TRV on passports as “stamping”. No need to engage in an unnecessary argument on that since you already know what they imply.It's important to avoid confusion so it is important to know what a visa is, a stamp is, a study permit is. These are basic immigration terms and this is an immigration forum.