Abstract: Techniques for identifying mention identifiers within a message using a mentions processor are discussed herein. In some examples, a communication platform maintains a mentions processor configured to receive a message including a mention identifier, analyze the message to determine a type of the mention identifier included in the message, identify a second user account or a virtual space referenced by the mention identifier, determine whether a notification should be sent to the second user account or the virtual space, and, upon determining that the notification should be sent, send the notification associated with the message to the second user profile or the virtual space. In some examples, an observability class associated with the mentions processor allows the use of a mentions lookup tool to view one or more stored mention identifiers associated with the message and one or more stored notifications enqueued for the message.