[Explanation] If the client has started a transaction, it is used. Otherwise a new transaction is started. (this is the default when no explicit type has been specified) [Type] 
REQUIRED
M A N D A T O R Y
R E Q U I R E D
R E Q U I R E S _ N E W
S U P P O R T S
N O T _ S U P P O R T E D
N E V E R