Thanks.

As far as I know it is not currently possible to get property
auto-completion from the property list of the file itself.

I don't understand: when I call "org-set-property" directly from the file (C-c C-x p), it does get all the property values in the file and proposes them for completion. I am probably missing your pint, could I ask you to explain?

Only when I use the "%^{prop}p" capture template element are the values not offered. I don't understand why because looking at the code of "org-capture-fill-template", it seems to simply call "org-set-property" for this element.

but you could still make use of the stock property in the template and auto-complete
from there

For instance:

("T" "TEST" entry (file+headline"/tmp/test.org" "drill")
        "** TEST  \n :PROPERTIES:\n :Effort: %^{prompt|0:10|0:20|0:30|1:00|2:00|3:00}\n :END: \n %^{PROMPT} " )

see the rest of the thread for more details http://lists.gnu.org/archive/html/emacs-orgmode/2011-10/msg01339.html

Yes I've read the rest of the thread, but that's not always feasible. In my use case, the property values are titles of academic journals, I can't list them all inside a "%^{prompt}" template element, I need them to be fetched from the file.

Thanks again.

Eric