The Texinfo export backend supports two approaches to writing Texinfo definition commands. One of them is described here, the other in Plain lists in Texinfo export.
The Texinfo export backend converts special blocks to commands with the same name. It also adds any ‘:options’ attributes to the end of the command, as shown in this example:
#+ATTR_TEXINFO: :options org-org-export-to-org ... #+BEGIN_defun A somewhat obsessive function name. #+END_defun
becomes
@defun org-org-export-to-org ... A somewhat obsessive function name. @end defun