Communication services enable users to communicate electronically over communication exchange channels using multiple modes of communication. Conversations between groups of users are common, where many communications may be exchanged repeatedly over a period of time. In some scenarios, a communication desired to be conveyed by a participant in a conversation may be a simple endorsement, such as receipt acknowledgment and various levels of social activity actions and/or gestures, which may be useful for other participants of the conversation to see as well. An endorsement indication based on the participant selected endorsement may be transmitted to the other participants of the conversation over a designated communication channel. The designated communication channel may be a control messaging channel in a transport layer of a communication service, for example, that is distinct from the communication exchange channels such that normal communication traffic may be unaffected by the distribution of the endorsement indication.