Expect Secretary of State John Kerry to be far more active on Twitter than his predecessor was.

On Kerry’s first day on the job, the State Department (@StateDept) tweeted that any messages directly from the big boss would be labeled with his initials, -JK.

#SecKerry will start tweeting from @statedept. Tweets from him will have his initials -JK

— StateDept (@StateDept) February 4, 2013

By contrast, former SecState Hillary Clinton barely dipped a toe into the social-media pool (in fact, the Loop sponsored a contest last year to help her craft her first tweet). As a senator, Kerry clearly enjoyed it, with recent tweets from @JohnKerry covering everything from the death of the owner of a Boston cannoli shop to the Pats’ Superbowl chances to a birthday shout-out to then-colleague Sen. Max Baucus (to whom he said “we’re still kids in this place.”)

A romp! worried re expectations but they came thru bigtime MT @bostonglobe @dan_shaughnessy think Pats are headed to SB b.globe.com/ST2Sw7

— John Kerry (@JohnKerry) December 11, 2012

But now that Kerry’s in the high-stakes world of international diplomacy, he might be in danger of sending mixed messages over a medium where meaning is easily lost. His sign-off, “JK,” for instance, is also online shorthand for “just kidding.”

Which could create some confusing diplomatic signals, IMO.