This is the official manual for the latest Org-mode release.
Buffer-wide header arguments may be specified as properties through the use
#+PROPERTY: lines placed anywhere in an Org mode file (see
For example the following would set
*R* (only for R
code blocks), and
silent for every code block in the
buffer, ensuring that all execution took place in the same session, and no
results would be inserted into the buffer.
#+PROPERTY: header-args:R :session *R* #+PROPERTY: header-args :results silent
Header arguments read from Org mode properties can also be set on a
per-subtree basis using property drawers (see Property syntax).
When properties are used to set default header arguments, they are always
looked up with inheritance, regardless of the value of
org-use-property-inheritance. Properties are evaluated as seen by the
outermost call or source block.1
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: :header-args: :cache yes :END:
Properties defined in this way override the properties set in
org-babel-default-header-args and are applied for all activated
languages. It is convenient to use the
bound to C-c C-x p to set properties in Org mode documents.
 The deprecated syntax for default header argument properties, using the name of the header argument as a property name directly, evaluates the property as seen by the corresponding source block definition. This behavior has been kept for backwards compatibility.