Linking to requests and users in my team

When I work on a request and have questions I would like to refer to a request to team members.
E.g. after a review I would like to send a message to a developer for a specific request:

hi @johnDoe, could you please check format of parameter foobar? Server responds error 'ArrayList cannot be cast to String

@johnDoe should receive a message/notification and be able to directly navigate to the mentioned request and maybe write back some answer…