Yet that is my task for this evening. My client formally accepted several articles from the last batch, which allows me to follow my tip:
BUSINESS TIP for Writing Client Articles: Explicitly track which articles your client has accepted, and share that list with your client.
I actually have a good relationship with this client; he does not go back and ask for endless tweaks and changes. Yet, even here, it is best to keep explicit track. So far it has been implicit: if he did not return an article with change requests, then I could "assume" it was approved. Now I can return to being explicit.