Note: This is about the IRC command voice. For the ChanServ command of the same name, see Voice (ChanServ)
A voiced user is one who has channel mode +v set on their nickname. Voiced users can talk in a channel regardless of whether or not the channel is set to +m, or moderated. A moderated channel bars all users from talking unless they have voice status on the channel or higher. For moderated channels, this is most useful for dispute resolution or for offering support to users one at a time. To voice nick1 on channel, you can issue this command:
/mode #channel nick1 +v
Many clients come with a voice command. If yours has this, you will need to consult your client's documentation for proper usage.
Outside of such channels, the channel operators may have other policies for the use of voice. This is up to the channel staff to decide and is not officially sanctioned by Ravenchat nor is it officially documented in the IRC protocol.
Services is capable of handling the automatic voicing and devoicing of users who have registered accounts. Therefore, manually voicing users is typically only useful for unregistered users or for support channels where automatic voicing is undesired. Services gives autovoiced users an access level of 3 in services listings. For users who have half operator access or above, they can autovoice nick1 on #channel with any one of the following four commands, roughly in order from least to most complicated:
/msg Chanserv VOP #channel ADD nick1
/msg Chanserv ACCESS #channel ADD nick1 AUTOVOICE
/msg Chanserv ACCESS #channel ADD nick1 3
/msg Chanserv FLAGS #channel nick1 +V