What do people think of some tags like "pre-1950" or "1980s", giving an age range.
I'm more interested in answering old house questions (1920's and 1930's), and also the tags might encourage a few more people to include age ranges.
"1940s" is a better tag than "old-house", "vintage" or "old-work", as age is subjective.
Tags can't be created before they are needed. They only exist because they have been added to questions.
Therefore, if a tag is needed it should be just added to the question and it will exist to be used by everyone else.
However, (and it's a big however) these "decade" tags smell like meta tags which are a "bad thing". I'm not 100% sure they are meta tags, but they are very close to being such. The test is
Does the tag work when it's the only tag applied to a question?
If the answer is "no" then it's a meta tag and shouldn't be applied.
Having said all that, perhaps if the tag included the age as well - e.g. 1920s-electrics (though I'm not sure that's actually a good tag either, but you get the idea) - then that might be the way forward.
The biggest advantage of the tags to me is how questions get grouped together, either browsing the tag itself or in the related questions. When viewing questions about 1920-era, you'll see some questions about door knobs, others about plaster walls, others about wood windows, etc. where the content in one question has very little to do with any other question in that category.
As ChrisF mentions, these tags on their own are meta-tags and shouldn't be used. See this blog post for SE's take on meta-tags along with this meta.so post about how to best tag questions.
These tags don't work because they say nothing about the questions they're applied to. If something goes wrong in in your house, and you come here for help, you're going to search for the name of the thing you're having a problem with, not how old it is.
Nor do these tags categorize questions in any useful way: if I have a 1930s house and have knob-and-tube wiring, searching for 1930s means that I'm going to miss out on any 1920s or 1910s questions about knob-and-tube.
Instead of focusing on the age of the house that your question is about, focus on the actual subject of the question.
Relevant to this discussion: The money stack site uses meta tags: https://money.stackexchange.com/tags/income-tax/info
How about this as a tag wiki:
[1930s]: For questions relating to a house component designed or built in the range of 1930-1939. This may be the only tag on a question, or combined with a component tag such as "electrical".
[pre-1800]: For questions relating to a house component likely designed or built prior to the year 1800. This may be the only tag on a question, or combined with a component tag such as "electrical".
These describe the question, and are not really subjective (they might require an estimation of age, but that itself does not make the tag subjective).
