If a person is found guilty of a sin, but repentent, they might be 'reproved' by the elders, either 'privately reproved' or 'publicly reproved' depending on the supposed severity of the sin and other, (sometimes quite arbitrary) factors.
In both instances, the person would lose their 'privileges', e.g. they would not be allowed to pray in behalf of the congregation, work at the magazine counter, control the audio system, or make comments in meetings etc. (They still have the 'privilege' of door-to-door preaching.)
In the case of a 'public reproof', an announcement is made at the meeting; I think it used to be something like "[name] has been publicly reproved for conduct unbecoming a Christian" and I think the current wording is something like "[name] has been publicly reproved and remains one of Jehovah's Witnesses".)
(If anyone notices that I've missed something, gotten something wrong, or if procedures have changed, please let me know.)