While I agree with you and I think parent's wording isn't the best, I think parent's point is that military tanks aren't liquid tankers or holding tanks like th

While I agree with you and I think parent's wording isn't the best, I think parent's point is that military tanks aren't liquid tankers or holding tanks like the term would have meant when the term was first used for military tanks, and military tanks were called that specifically to give little insight into what they did. Now no one takes issue with a military tank being called a tank.