Since there's no specific "background/setting" forum, this will have to go here. For those unaware, rivet counting is a term that comes from historicals and refers to people with a borderline unhealthy interest in the minutiae of their area of interest - a definition I'm fair certain applies to many of us ?
Of course, it's a bit more difficult to be a rivet counter in Star Wars given the history of the franchise's multiple different "tiers" of content canonicity and the sometimes maddening disregard for consistency. Rarely is the issue more evident than when it comes to the depiction of Imperial military ranks and insignia.
You have the ostensibly meaningless system from ANH where plaques were designed and assigned based on "it looks cool on that dude". You have the genuinely weird ESB system that is so compressed, even accounting for the silly "code cylinders also help indicate rank" convention, you can only cram in eight or so ranks for the entire command structure, and which led to the truly awful mess of a chart in the Warfare sourcebook trying to reconcile it, and then of course you have RotJ where a costume department error led to every Imperial officer getting an ESB-system Commander plaque regardless of actual rank. Still, based on just the three original films, there was a "standard" conception of the Imperial rank structure: the ANH-era stuff was sector-specific and so had a lot of variation, the ESB-era versions were a universal replacement that came about in the post-Yavin reorganisation of the Imperial military, and RotJ's mistake is ignored.
And then along came Rebels and Rogue One and nuCanon comics, and fouled that right up. Now, I didn't care for the convention that had previously developed, trying to in-universe explain away the ANH-era inconsistencies was a mistake IMO and the daft ESB replacement system was, well, daft, but it was at least a standard. We now have more structured ANH-era insignia and also the appearance of ESB-era insignia pre-ANH.
I spent a good long while bashing my head against the wall trying to develop something that reconciles all of this nonsense, given Lucasfilm seem disinclined to bother, but in the end I found someone else's effort much more compelling and comprehensive than anything I'd managed - Himser over on stardestroyer.net(be warned, the forum generally would definitely meet Old Ben's definition of a hive of scum & villainy ? ) has put together a chart that manages to systemise almost every screen example of ANH-style ranks(a handful have to be ignored because of their inconsistent IRL conception) in a way that allows for a full command structure with divisional variance, AND reconcile it with the ESB insignia being used at the same time, AND divorces code cylinders from rank entirely as it should be. It's not "canon" of course, and some people will choose to depict only what appears on screen regardless of how much sense individual screen appearance make relative to each other or any external standard, which is an entirely valid way of going about things, but for myself I crave these kinds of comprehensible systems and will be using the chart below.
What's everyone else's view - obviously some won't care either way, but I'd be interested to hear from people who prefer the "screen only, regardless of consistency" approach as to why they prefer it.