Could Jellicoe prepare Russian cooperation without revealing the plan?

How much could Jellicoe coordinate with his Russian counterpart before the Baltic operation?

He could build a professional relationship and discuss readiness in general terms while withholding operational details that enemy intelligence might intercept.

Jellicoe could begin regular personal correspondence with the Russian Baltic commander without mentioning the operation. Letters about family, fleet administration, and infrastructure would create familiarity before a crisis. Both admirals would assume that enemy spies made their correspondence a priority. They would therefore exclude hypothetical operations, individual ship capabilities, and other useful intelligence. Once Britain entered the Baltic, the professional relationship could help the commanders cooperate despite the lack of advance operational coordination.