Group mentions provides you the admin of Jira to put in simple and effective controls in place to get the best out of Group Mentions and prevent any misuse of it.
Group mentions will only allow a group to be mentioned if it has access to the project/issue in which the user is trying to mention on.
Member of only – Default enabled.
When enabled, Group mentions will restrict a user from mentioning groups a user is not a member of in addition to the default restrictions mentioned above.
Add as watchers
Enabling this will add all of the group members as watchers to the watchers of an issue/ticket when mentioned.
! Enable this with care.
Groups can be prevented from being mentioned when they are selected to be excluded. They will be prevented from getting mentioned even if the user is a member of an excluded group.
There is always an exception, so we have included one in Group Mentions. If you wish to enable a user and allow him/her to mention groups, that he/she is not a member of and even mention excluded groups they can. They need to be a member of the group that is configured as an exception.