I just noticed a somewhat redundant tags, like this question about the IBM 360/20 carries the tags ibm mainframe and s360. Here mainframe is kind of an outlier by being overlapping with s360. After all, all /360 are mainframes by definition. Accepting the logic of overlapping/redundant tags would mean that all questions regarding any micro computer get a tag microcomputer added (*1). Similar for all minicomputers (*2).
As similar pile up of duplicate tags can be found in other places, for example this question about a certain Soviet ZX Spectrum clone, tagged with hardware zx-spectrum ussr zx-spectrum-clones clone. Here of the three tags zx-spectrum, zx-spectrum-clones and clone, one (zx-spectrum-clones) is essentially the combination of the other two (*3). If it's about a spectrum-clone (and not a spectrum), then neither of the other two are needed.
This brings up another such combination including manufacturer tage together with model/family tags like apple plus tag:[apple-ii], or as mentioned ibm and s360. Including a manufacturer without need simply narrows down the application of the question, doesn't it?
So while the first instance is about adding a (way) generic tag that describes something implied in a more specific, the second does feature a generic sub-qualifier(spectrum + clone), to be accompanied by a very specific tag including both. Somehow neither seams a logical and even less useful combination. How to handle either?
All of this is not only important in terms of logical clarity, but as well due the 5 entry limit for tags, obviously meant to avoid an overblown tag cloud.
*1 - Which opens the question why there is an overly specific tag of 8-bit-microcomputers and why it gets attached to questions about any word size machines.
*2 - Which BTW in itself carries the oddity of being set in plural.
*3 - Which again adds the question why there's a plural on 'spectrum-clones', but not on 'spectrum' (as there were as well multiple) and vice versa.