I have seen a few cases where the tag excerpts suggest not using the tag, or trying a more specific tag, but I have not come across the case where a tag suggests using a different Stack Exchange community, I searched but can't find anything that suggests it is bad etiquette.
My reason for wanting to do this is that I have seen that some tags exist in multiple communities but the poster is much more likely to get a response in one community rather than another just because there is more traffic there on that tag, or the tag is slightly more on-topic for that community in a specific situation.
My initial case that prompted me to post this here involves a question I posted that does not seem to be getting much attention in one community that may actually have got more chance of an answer with the same tag in another community. I asked a question in Unix & Linux with a tag of denyhosts at the time it seemed appropriate and although there wasn't a great amount of traffic the tag had some use even though it had no tag wiki content at all. As days have gone by and there have been very few views, no answers and no upvotes - I am left wondering if the question wouldn't have been better made in ServerFault with a tag of denyhosts and am weighing up the pros and cons of asking for migration if after a few more days there is still no activity. It struck me that I could have avoided this if the tag wiki excerpt had warned me that this tag was perhaps more active over there - I understand my bad for not researching well enough but why not make people's lives easier.
Neither tags initially had any tag wiki content. I have added an excerpt on ServerFault and was thinking of how to word the excerpt on Unix & Linux.
Although I appreciate answers to my specific case I do understand that this question would be better asked in one of the meta communities (which?); and am asking here because I think there could have been a generic etiquette to this kind of situation across all Meta Stack Exchange communities. Each individual tag situation will have its own merits, I am looking for general etiquette advice, and/or steps to follow in a community when faced with this situation.