While there are some criteria to distinguish a real life battlecruiser from a battleship, on Danbooru the battlecruiser are visually indistinguishable from a batttleship, especially for those who did not have knowledge about naval warfare.
Basically, almost all of the "battlecruiser" posts are just posts with the Kongou-class battleship appeared in it, which makes it feel like canon tagging. So, I think the tag should be merged with battleship to clear up the unnecessary pedantry.
For what it's worth ships like Kongou were also classified as "fast battleships" in addition to "battlecruisers", so it really isn't a stretch at all just to ignore "battlecruiser" in their case.
I have to disagree with this BUR, they're very different concepts. Just because someone completely unfamiliar may not easily be able to identify the differences does not make a tag bad. Someone unfamiliar with firearms may have trouble distinguishing between the countless AK varieties (speaking from experience). Doesn't mean we alias them all to kalashnikov rifle, they're implied instead (Edit: Some aren't even implied due to being unlicensed derivatives, further complicating things). Someone unfamiliar with clothes from a certain culture may have difficulty distinguishing similar garments. This also does not make those tags bad. One's grandparents might not know the difference between a playstation 2 and playstation 3, they might even call them both a "Nintendo", but that doesn't mean we alias all console's tags to "console" or "nintendo".
It's also incorrect to say they're pretty much all Kongous. Most of the posts are Kongou-class ships, but there's also hms hood, hms repulse, and others. Maybe fixing posts missing the tag would be better than aliasing.
It's also important to note that there is a distinction between calling something what it is and "canon tagging".
Edit to reply to what Shinjidude said while I was writing:
Shinjidude said:
For what it's worth ships like Kongou were also classified as "fast battleships" in addition to "battlecruisers", so it really isn't a stretch at all just to ignore "battlecruiser" in their case.
They were initially built as battlecruisers but after Japan withdrew from the London Naval Treaty they were remodeled and classified as fast battleships, hence various sources referring to them by either of those two classifications.
I agree with most of this, and am not really in favor of the BUR, just arguing that Kongou class can go both ways. I will also note that we have conflated things to be more general in the past though, e.g. pistol -> handgun even though the two aren't semantically identical (not all handguns are pistols). By the same token we also kept revolver since it's so visually distinct.
... especially for those who did not have knowledge about naval warfare.
Something requiring a bit of background knowledge does not automatically make it canon tagging. I'm by no means a shipfucker myself, so I wouldn't know the finer details, but it seems pretty clear to me that, although minor, there are actual differences
Also, @TrueKringe , can you please stop editing wikis and tag definitions if you're unsure what the wikis are saying, and before any discussion has been made on the forums. I've had to revert a few wiki edits because you changed the wiki definitions and then submitted a BUR suggesting that change be codified, that's the wrong way around.