The South African cricketer had a good Test debut, hitting his first ball for a four and then taking a wicket (of the opposing captain AN Cook) off his first ball. He ended up with a relatively modest return, as you can see from the scorecard:
http://www.espncricinfo.com/ci/engine/match/800465.html
Apparently he is only the second to achieve this double on debut. The first was M Henderson of New Zealand, in his county’s first ever Test:
http://www.espncricinfo.com/ci/engine/match/62572.html
That match is more remembered for MJC Allom’s hat-trick (and 4 in 5) on debut. And Henderson never played in a Test again.
Coming back to Hardus Viljoen, he may well avoid Henderson’s fate and play in more Tests. But there is something odd about him.
Those who compile cricketing records like everything to be black and white, with every run scored and ball bowled being accounted for. But what if even a person’s name is uncertain? That happens often enough in parts of South Asia where a person may have a given name, a middle name, a surname and perhaps several other names. Now we have a mystery from South Africa.
Starting with this Wikipedia article:
https://en.wikipedia.org/wiki/Hardus_Viljoen
His name is listed as Gerhardus C Viljoen, with Hardus apparently being a contraction or nickname. But what does the C stand for?
The Wikipedia article has links to two of the major databases:
http://www.espncricinfo.com/ci/content/current/player/375126.html
which gives his full name as GC Viljoen
and:
http://www.cricketarchive.com/Archive/Players/373/373892/373892.html
which states that “GC is his name, not his initials”
Of course, there are a number of people who have initials which do not mean anything-including an US president, no less.
This is the relevant bit about Harry S Truman’s middle name:
“Harry S. Truman was born on May 8, 1884, in Lamar, Missouri, the oldest child of John Anderson Truman (1851–1914) and Martha Ellen Young Truman (1852–1947). His parents chose the name Harry after his mother’s brother, Harrison “Harry” Young (1846–1916). They chose “S” as his middle initial to please both of his grandfathers, Anderson Shipp Truman and Solomon Young. The “S” did not stand for anything, a common practice among the Scots-Irish.“
This is perhaps the most famous picture of President Truman, after the 1948 elections:

Here are a few more people who have initials which do not stand for anything:
http://mentalfloss.com/article/26920/quick-10-people-fake-middle-initials
Even the fans of MAD magazine would not know Alfred E. Neuman’s middle name.