Am I correct with the following interpretation?
The CEO wisely sent the letter using an official headed paper so the committee would not complain about lack of identification.
official headed paper = a paper with headings containing logo, identification, address, telephone etc. used by entities to formally communicate.
The word that was used to describe this type of paper, preprinted with the organization's name and address, was letterhead. But since the advent of the PC and the internet, both the type of paper and its name are in extremely rapid decline.
I just wanted to state that the CEO knew he couldn't simply write all IDs there himself as a committee would require 'official' identification.