Getting from STALAG IXC to Barcelona in 1943

[ajf25]

Can anyone solve my conundrum?

I have an Australian Soldier, William Derek Curtis (b. 1908) who was captured in Greece in April 1941. 

https://recordsearch.naa.gov.au/SearchNRetrieve/Interface/DetailsReports/ItemDetail.aspx?Barcode=4848706&isAv=N

He spent 5 months in Kokina Camp in Athens (according to his answers in a questionnaire regarding his captivity)
1 Dec 1941 - recorded as being in Stalag IXB (Lazarette Dieburg, Germany)
14 Aug 1943 - recorded as being in Stalag IXC (Muhlhausen, Germany)
27 Oct 1943 - embarks at Barcelona, Spain
3 Nov 1943 - recorded as being previously POW, now arrived in Eygpt.
30 Dec 1943 - embarks Eygpt, arriving in Sydney 27 Jan 1944.
He was discharged from the army on 6 Nov 1944, the reason being there was "no suitable vacancy in which his services could be employed".  His file is also stamped as being PROTECTED PERSONNEL.

My questions:
How did he get from Stalag IXC, where he was in Aug 1943 to Barcelona by Oct 1943?  I can't see anything in his file about escape, but being totally ignorant of such things, maybe it wasn't recorded.  The camp wasn't liberated until April 1945.
What does Protected Personnel mean?

Alison 

[ShaunJ]

He was repatriated in an exchange of prisoners. https://trove.nla.gov.au/newspaper/article/247807870?searchTerm=%22nx9243%22

The report includes an explanation of Protected Personnel.

[ajf25]

Wow, thanks ShaunJ, good find.
I had looked on Trove but with his given names rather than his initials.

Cheers,
Alison

[ShaunJ]

I had looked on Trove but with his given names rather than his initials

I searched for his service number NX9243.

See also https://gallery.its.unimelb.edu.au/imu/imu.php?request=multimedia&irn=37047

[ajf25]

Thank you