A group is a simple data structure that maps a group name to a set of group member names. It can be used e.g. within ACL definitions to specify groups of users. The group name usually is something like EditorGroup (some word ending with Group). This default pattern can be changed (e.g. for non-english languages etc.), see page_group_regex on HelpOnConfiguration. The group members are just arbitrary names (unicode strings). Note that groups are not limited to user names, you can also define a group of your favourite wiki pages (but you would need some code that uses that group in a somehow useful way).

You can create a group definition for a group named EditorGroup by creating a page called EditorGroup with this content: Important: Group members have to be on an unordered first-level list. If link markup is used, the link target will be added as member. Please only use rather simple link markup. Everything else (other text, second-level items, etc.) is ignored. You have to explicitly use the group (there are no hardcoded group names in moin), see below.

Use groups to define permissions for those users on your wiki (see HelpOnAccessControlLists). For example, you could have this in your wiki config: Of course you can also use the group in on-page ACLs:

If your default ACL allows writing for everyone, it is a good idea to protect critical group definition pages with some more restrictive ACL. E.g. on a group definition page AdminGroup: As you see: only members of this group may write to the group definition page (and of course everyone who gets write rights from acl_rights_before in the wiki config).

You can also add names of other groups as group members, that is the same as including all their members directly.

MoinMoin can also use group definitions from other sources, but this needs to be configured in your wiki config. See groups on HelpOnConfiguration.