PP
Don't get why you're confused, you gave the distinction yourself:
When instructed by the ATS Unit to 'pass your message', the reply should contain the following information, Whenever possible in the order specified:
A) Aircraft call sign \ type
B) Departure point & destination
C) Present position
D) Level
E) Additional details / Intention
and
Position reports shall contain the following elements of information:
A) Aircraft identification
B) Position
C) Time
D) Level
E) Next position and ETA
See?