This is the official manual for the latest Org-mode release.
By default, code blocks are expanded with
during tangling. This has the effect of assigning values to variables
:var (see var), and of replacing “noweb”
references (see Noweb reference syntax) with their targets. The
:no-expand header argument can be used to turn off this behavior.
:no-expand header argument has no impact on export,
i.e. code blocks will irrespective of this header argument expanded for