I think I've found the answer to my question, but it prompts me to report a bug:
The options in Settings are shown as
• Don't send email updates
• Send daily summaries
• Send combined updates (25 messages per email)
But the subject lines in the email messages are
• Digest for
rec.mus...@googlegroups.com
• Abridged summary of
rec.mus...@googlegroups.com
I went looking for help, and found this in the forum (
https://support.google.com/a/forum/AAAA034zvV8Vd46UcRYz6M?hl=en&authuser=0#):
>>>>>
Google describes abridged email updates as a single email summary of new activity -- including messages from users and administrators -- per day. Digest email shows the full content of up to 25 messages in a single email per day. While you can see the sender, subject and a brief summary with abridged emails, you can view all text and images from all group activity in the digest email. For groups that have more than 25 new messages, you will receive multiple digests.
Read more:
http://www.ehow.com/info_12115201_difference-between-abridged-email-digest-email-google-group.html#ixzz2wso7rzvC
<<<<<
So
• the "daily summaries" in the Settings are the "Abridged summary" emails
• the "combined updates" in the Settings are the "Digest" emails.
or in table form (hope this works)
Settings Email header
"daily summaries" "Abridged summary"
"combined updates" "Digest"
"Confusing" is hardly the word for this. DEAR GOOGLE, PLEASE USE THE SAME TERM IN BOTH PLACES.
The only way I can see to point this out to Google is via admin help in the Forum, but only an admin can do that. Who's admin for this group?
-- Mark