The second part of J.R.R. Tolkien’s full name was Ronald.
J.R.R. Tolkien’s full name was John Ronald Reuel Tolkien. The initials in his familiar author name therefore stand for John, Ronald, and Reuel. Ronald was his middle name, while Reuel was an additional given name that Tolkien used as part of his formal identity.
Tolkien was baptized John Ronald Reuel Tolkien in Bloemfontein on 31 January 1892, several weeks after his birth. The name Reuel had family significance and also appeared in the name of his son John Francis Reuel Tolkien. Tolkien generally became known publicly through his initials rather than by using all three given names in ordinary presentation.
The names John and Reuel can therefore create confusion when a question asks specifically for the middle name. The requested position is the second given name, not the first initial or the final given name.