Half shaft question

All,

I've picked up a pair of extra/spare half shafts for my cars and
have a question.  Is there a way to tell regular half shafts from
hardened shafts?  I've seen reference to a "C" being added to the
stock number, i.e., TBA 806 = regular, TBA 806C = competition.
The shafts I've acquired are marked "TBA 806 EN170 MesboMOWOG".
I 'assume' that these are regular shafts am I correct?
TIA
Biff Jones
Pasadena, MD
'59 Bugeye, "Kermit'
'62 Sprite, 'Ole Gray'
http://sprites2.homestead.com/index.html