Hello,

There seems to be an old thread about this but I didn't find an answer
there:

http://lists.gnu.org/archive/html/emacs-orgmode/2011-10/msg01079.html

If, from an org file containing two entries with respective values "foobar"
and "foobaz" for property "prop", I call "org-set-property" to set property
"prop", then the two values "foobar" and "foobaz" are offered as
completions.

But if I define a capture template with that file as target and the element
"%^{prop}p" in the template, then no completetion is offered when I am
queried for the property value. That makes this template element much less
usable in my opinion. Is it a bug?

I tested with "emacs -q"
GNU Emacs 26.1 (build 1, x86_64-unknown-cygwin) of 2018-05-28
Org mode version 9.1.13 (9.1.13-elpaplus @
/c/test/.emacs.d/elpa/org-plus-contrib-20180604/)

I'm happy to help with further testing if needed.

Thanks in advance,

Eric