I have obviously made the mistake of mentioning comments on appearance as being a micro-aggression, since it's frankly a terrible example and you seem to have latched on to it. Commenting on appearance in such a way it makes someone uncomfortable, repeatedly, is pretty blatantly harassment and not a micro-aggression.

I think you are still misunderstanding what a micro-aggression is. I doubt 99% of the American population has even heard the term, and 99.999% of them don't understand it well enough to make a conscious effort to never use them. To suggest that it's "not that complicated" is simply not true.

Harassment is not a micro-aggression. Most anyone who uses the term "micro-aggression" is not referring to blatant harassment.

What is the comment that is perceived as a micro-aggression which you feel you should be entitled to make after it has been made clear to you that the comment is unwelcome?

Again, you're missing the point of what a micro-aggression is. Micro-aggression is not about the repeated use of language to a specific, individual person, who has shown previous discomfort to that language. That is pretty much the definition of harassment, which again, is not a micro-aggression.

A micro-aggression would be asking Allison, during a discussion about something in our childhoods, "Where do you grow up?". Unknown to me, Allison actually grew up in Bolivia, and she is sensitive about discussing it because she feels people discriminate against her because she's an immigrant. I have micro-aggressed Allison. It has nothing to do with repeatedly asking this question, or similar questions, about where she grew up.

If Allison did respond in an uncomfortable manner to this question, I should be receptive enough to pick up on this and avoid asking further questions that might be related. Continuing to do so at that point is harassment and not a micro-aggression.

Policies against harassment are good. Policies against micro-aggression are a difficult subject, but the obvious answer isn't that "workplaces should definitely fire people for repeatedly and unknowingly micro-aggressing a variety of people".

No, that's what you're saying it is. And the claim that asking where "Allison" is from would result in you being fired is also yours and yours alone.

Am I correct in assuming that the answer to my last question is "there is no such comment on a micro-aggressions list that is OK to make to a colleague after it has been made clear that such comments are unwelcome"? If that's the case, we have nothing to argue about.

I don't believe in even the most strict enforcement of an anti-micro-aggression policy would you get fired for a single instance of it, but the point is that you can make similarly innocuous comments, each aggressing in a unique way, to multiple people - which could be enough to get fired.

And I guess we have nothing to discuss. There is no comment that is okay to repeatedly make to the same person after it's been clear that it's uncomfortable to that particular person because that is then harassment. However, just because Allison didn't like the "Where do you grow up?" question doesn't mean it's harassment to ask that of someone else (though it could still be another micro-aggression).

I am not sure why you're specifying that this is "my" definition of a micro-aggression. This is the most common, and widely accepted, definition of "micro-aggression". It is possible the person quoted misused it.

No, what's happened here is that you insist on conflating the concept of micro-aggressions with your inference of what a particular company meant by them "not flying there". To wit: you presume that if you make a benign comment about someone's hair or shoes or math talent, you'll be fired abruptly. That's a caricature of reality.