I, and others, have been using the #scicomm hashtag since 2008 (which is when I joined Twitter, and I joined it mostly because of science communication activities going on). When I began ScicommJobs in 2009 I added the jobs tag to that one for the purposes of autoposting to Twitter.
To me a double tag means it reaches two lots of people – anyone following #scicomm and anyone following #jobs.
I’ve noticed a few people using #scicommjobs as a hashtag and wondered if I should use that instead?
If everyone prefers #scicommjobs let’s go with that, but of course it also means those following #scicomm don’t see it…