org-babel-exp-call-line-template

org-babel-exp-call-line-template is a variable defined in `ob-exp.el'.
Its value is

""

Documentation:
Template used to export call lines.
This template may be customized to include the call line name
with any export markup. The template is filled out using
`org-fill-template', and the following %keys may be used.

line --- call line

An example value would be "\n: call: %line" to export the call line
wrapped in a verbatim environment.

Note: the results are inserted separately after the contents of
this template.

You can customize this variable.