I thought that I had demonstrated that the historic meaning of the flag has not had time to change. Here is a great proof that the meaning hasn't changed and the the people waving it know it.
The people that brandish this flag have to attach an addendum to qualify that they don't think that their symbol means what you think it means.
No, they have to use the addendum because you keep trying to shove your opinion down their throat. Much like atheists have to keep using addenda about how their stance doesn't mean they hate god, but that they simply lack the belief in deities, or how Gamergaters keep having to say "Actually, it's about ethics in video games journalism", or how (some) feminists feel the need to point out that they don't hate men. Regardless of the validity of any of these claims, the reason they have to keep making them is that their opposition keeps trying to force a certain narrative on them instead of letting them represent their own views.
Personally, I'd argue that those who fly the flag are likely to know better what message they're trying to send when they fly it than you do (n.b. I do assume that you don't fly the Confederate flag. I don't think that's too controversial an assumption). They were even kind enough to write it out for you in a fancy red-and-blue font, so you don't have to guess.
I agree some of the meanings behind the symbol of the Confederacy has changed, but the salient meanings of hate and slavery have not. This symbol still means these things. If it didn't, then no one would care that it's on a flag. However, as it stands, the Confederate flag means many hateful things that a state should not be endorsing; whether implicitly or not.
In saying that, you're saying that those who think the flag is racist are right, while those who say it's not are wrong. To justify this, you use the fact that some people claim it's racist. That's not on.
To continue with our Nazi analogy, members in the KKK will occasionally use the swastika to convey a meaning of white supremacy. They don't attach the political and economical issues associated with the Nazi party that created our contemporary meaning for the swastika, but again, the salient points of white supremacy are still there. So while the meaning of the symbol has changed, it still represents more or less the same thing. Likewise, if the meaning of the Confederate flag had changed, there would be no reason to attach a caveat about heritage.
You just said it's possible to use a well-known symbol to mean something else than what it originally meant (swastika as white supremacy rather than swastika as Nazis). That, to me, sounds like an attack on your argument, not a defence of it.
Let me see if I can sum up my replies in a few paragraphs; I'm loath to engage in deeply branched quote trees. While I may not have ever lived in Mississippi, I spent 29 years living in the American South. I lived in both Kentucky and Georgia and these years constituted both my formative years as well as the vast majority of my life. In this time, I formed an opinion about the Confederate flag standing for racism, hate, bigotry, ignorance (especially in the case of individuals from West Virgina), and oppression. All this talk about me telling them what their flag means, feels to me more like I'm telling people what a flag that's been flown over my head feels like to me.
Regardless, my background aside, it's ludicrous to argue that the Confederate flag does not mean racism. I typed in "confederate flag" into Google and the fourth predictive result, right after history, was "confederate flag racist."
The Confederate Flag means racism. This should be an axiom.
Now, I am fully aware that people say that it does not mean racism and I do maintain that they are wrong. You don't get to hang a swastika somewhere and claim it means environmentalism. You cannot rewrite the meaning of a symbol because you don't like part of it. It's what I was saying earlier about a failure of communication. If you want to have a symbol that represents your Southern heritage and don't want people to think you're racist, then pick something different than a Confederate flag. Semiotics is a serious field of study with deep insights into not only how people perceive things, but also the way in which we associate feelings of loyalty, aversion, and pride; to say that all that can be undone by whatever the person flying the symbol thinks is frankly arrogant.
Now, I will fully admit that it's my opinion that the Confederate Flag means racism, but it's not a lonely opinion. While it may not mean racism to everyone, one of the core meanings of the confederate flag is racism. When you use that symbol, you get that meaning. Plain and simple. When the KKK uses the swastika, they are achieving the white supremacy meaning that they desire, but they are also getting strong antisemitic feelings attached to that. If the KKK said that they are just using the swastika to only mean white supremacy (I don't think they would, but lets pretend) they can't change the feelings that the symbol evokes in those that see it. If the KKK wanted to use the swastika to convey a meaning of only white supremacy, then they are doing a very poor job of communicating.
However, as it turns out, the KKK doesn't mind getting these other elicitations because the symbolism of the swastika so closely aligns with their ideals. I was criticized for this sounding that I was making an argument for symbols being able to mean different things. It was in part (they can mean different things, but one meaning does not invalidate the other meanings), but what's really at work here is symbols can mean many things. Lets say that the swastika means three things: Ayran supremacy, environmentalism, and Nazi Germany. The KKK has no environmentalism agenda as far as I'm aware, but white supremacy is very close to Ayran supremacy and the things that Nazi Germany did do achieve Ayran supremacy align closely with the KKK's goals. What about environmentalism? Well, they don't much care for that, but that's fine because the swastika still is very close to their message and does an effective job of communicating their ideals. Now, if an environmentalist group wants to use the swastika, because in our pretend scenario the swastika also means environmentalism, they cannot lose the Ayran supremacy or Nazi connotations associated with that symbol simply because they don't' want them. One meaning does not invalidate the others.
People flying the Confederate flag cannot lose the meanings of racism associated with the symbol no more than our pretend environmentalist group can lose the negative connotations associated with the swastika.