This is the official manual for the latest Org-mode release.
Header arguments are also read from Org mode properties (see Property syntax), which can be set on a buffer-wide or per-heading basis. An example of setting a header argument for all code blocks in a buffer is
#+PROPERTY: tangle yes
When properties are used to set default header arguments, they are looked up
with inheritance, regardless of the value of
org-use-property-inheritance. In the following example the value of
:cache header argument will default to
yes in all code
blocks in the subtree rooted at the following heading:
* outline header :PROPERTIES: :cache: yes :END:
Properties defined in this way override the properties set in
org-babel-default-header-args. It is convenient to use the
org-set-property function bound to C-c C-x p to set properties
in Org mode documents.