I need something that can help me tell if a house guest has communist brainworms, but doesn't signal anything to the uninfected. I was thinking something like a print of one of the Diego Rivera murals where Lenin is lurking in the background. I need some more ideas. It could be music, some choice phrases, some prominently displayed literature, etc. But it has to only be meaningful or interesting to the already initiated.
Edit: My wife is pretty sure that a normal American does not know what Lenin looks like. However, a portrait of Lenin won't work as a shiboleth if I'm asked to explain who he is.
I've had some situations like that, and then they ask if I'm a communist. When I say yes they just laugh.
I did find a fellow traveler once while going on a rant about how some industry needed to be nationalized.
I think we have a positive obligation to engage in ideological struggle as communists. A lot of times people are very flippant and ineffective about it which is counter-productive, but so is accepting defeat on every point. Ultimately though, the PMC workplace is not the great site of struggle. Us as PMC revolutionaries, our main responsibility is to paypig our proletarian comrades until we are so fed up with the contradictions of our position that we commit class suicide. Or as in the case of nurses and teachers in many countries, our roles become so thoroughly proletarianized that we are able to start agitating and organizing in our workplaces as a direct site of struggle.
Finally, if you are not a part of a larger organization, it is difficult to start agitating or organizing in your workplace (when it is a PMC workplace where there cannot be an internal labor struggle) because you do not have an outlet for the energies you are trying to awaken in your colleagues. The primary goal then should be to start joining that organization or building it if there is nothing worthy locally. Only in the later case would your shibboleths be helpful. I think if your workplace is a site of acute class struggle then you can be more direct in your propaganda.
I've been there, and frank amd honest organizing was easy. Where I'm at now there's no class consciousness at all. I don't know if it's the work environment, regional culture, or the cumulative impact of nationalist propaganda.