The "code of conduct"

which was recently passed out to the members of a group I belong to has missed something important. It does not acknowledge the need to thank people.
Now perhaps they thought it was already covered in the part which says "show courtesy". I don't know and I am not likely to find out.  I don't even know where they got the code of conduct from but I suspect that the committee did not write it.
There is an item in the code which says "encourage all members to participate in meetings and activities". Perhaps the thought is that the need to thank people is included there without actually saying it.
My own feeling is that it needs to be there in a much more direct way. We should be saying something about "acknowledging participation" perhaps? 
The current President handed out "certificates of appreciation" to people who had done certain things during the past year. I was given one of those and felt acutely embarrassed by it for a number of reasons, not least because I was never thanked for other things I did which involved a great deal more time and effort. It was the same for some others.
When I joined the group many  years ago there was an elderly man who used to come along to meetings. He was there only briefly. He would give the Treasurer's report and then leave again. Yes, he was the treasurer although he had no other association with the group. His wife had been a member. He went on doing the job after she ceased coming. He went on doing the job for quite a number of years. The husband of another member was the auditor. Both of them did a great deal for the group. 
The thanks to both men was, at best, perfunctory. Their work should have been formally acknowledged at a meeting and some sort of presentation given to them. They should perhaps have been invited to attend the Christmas lunch. It never happened.
After he had ceased to do the job I sometimes saw the former Treasurer and his wife in our local shopping centre. On a couple of occasions I went as far as to buy coffee for them and sit there and chat for a bit. I did it because I felt so guilty about the way he had been treated. He opened up just once and said he was "disappointed" he had not been thanked. I could see it hurt.
I knew how he felt. I had done a job for the group for fourteen years and never been thanked.  I was doing something else and been simply told abruptly to cease doing it. Such things do not encourage people to volunteer or participate. 
Saying "thank you" is about more than casually saying the words. True appreciation of something someone else has done for you or for a group is what encourages further participation.