Taboo

This appears to be a class of magic rather than a specific spell, as we are told that "the name has been jinxed," with "a Taboo"¹ rather than with "the Taboo."

The very existence of this thing in book seven is, in and of itself, a plot hole. The tone gives the impression that Ron is so familiar with it that it should not even need explanation. On the other hand, Hermione has clearly not heard of it before, and it has never before been used to explain the fear of using Riddle's name.

If this is a common thing, someone should have said something to the effect that using Riddle's name called down Death Eaters during the prior war.

If it is a brand new thing, Ron's explanation, while it does have all the necessary information, should have more wonder and surprise that this is possible, and not "why do you not know this" to it.

If is well known but restricted in some way, what does the restricting? Why (for example) must one control the Ministry to set a Taboo?