The digest version of the list is a list version where people receive postings to the list periodically (e.g. once a day) or when a large number of posts have accumulated. Digest subscribers are in the <listdir>/digesters.d/ directory.

The nomail version of the list is a list version where people are subscribed like usual, but they won't receive any postings to the list. This is useful for people who read the mailinglist through a news gateway, but want to be able to post to the list. Nomail subscribers are in the <listdir>/nomailsubs.d/ directory.

Unless the -U switch is used it will switch its user id to the user id owning the list directory. This is done to make sure that new files created are having correct permissions.

If the given address is already subscribed to the list, but to a different version, the subscription is switched to that version, and confirmation and moderation are bypassed. If the address is already subscribed to the version requested, a mail is sent to the subscriber, unless the -s switch is used.

Subscription may be moderated (if <listdir>/control/submod exists) unless the -f switch is given. When a subscription is permitted by a gatekeeper, welcome messages are sent to the subscriber as usual, regardless of options given now.

To ensure subscription is silent from the point of view of the subscriber, use -f, but neither -c nor -C. To inhibit notification of the owner, use -q. Use of -s is recommended to ensure you don't spam already-subscribed addresses by accident.