This is the official manual for the latest Org-mode release.
:no-expand
By default, code blocks are expanded with org-babel-expand-src-block
during tangling. This has the effect of assigning values to variables
specified with :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.