If you have been listening to a conversation and you want to make a brief comment (typically a single transmission) relevant to the conversation, but you cannot join into the conversation for any appreciable length of time, you should break into the conversation during the courtesy tone interval by stating your callsign followed by "comment" or "with a comment." Once another station has acknowledged you and invited you to make your comment, proceed do so followed by turning it back over to the station who invited you to comment, or in the case of a roundtable, to the next person in rotation, and clear your station by stating your callsign. As in the case of joining a conversation, be mindful when contemplating whether or not to break into a conversation to interject a comment.