Hi,

It would be nice if the documentation mentioned the need to reparse the
org buffer with `C-c C-c' when a property is set with #+PROPERTY.
(info "(org) Property syntax")

And, IMO, it should also be mentioned here:
(info "(org) Buffer-wide header arguments").

A simple footnote like the one present here:
(info "(org) Tag inheritance") should be sufficient.

> (1) As with all these in-buffer settings, pressing `C-c C-c'
> activates any changes in the line.

-- 
Daimrod/Greg