I had written an article on another site which I felt was relevant to a question here, so I decided to re-post it as an answer. However, it ended up flagged and deleted as plagiarism.
Obviously the charge of plagiarism is unfounded in this case since I had written the original and it remains entirely my own work. What recourse is available to me, and how can I prevent this from happening again in the future?
In cases where text is unattributed yet clearly copied from a third-party site, classifying it as plagiarism is a fairly easy mistake to make. This is especially the case with the Internet, where even when users don't post anonymously, actually proving their identity is often unfeasible.
The best preventative is as simple as it is effective: Attribute it anyway, just attribute it to yourself. Simply come out up front about the fact that it was originally posted on a third-party website, you felt it was relevant to the answer, and summarize/quote/rework it to fit the actual question asked, just as you would any other source.
And if the only problem with your deleted post was a mistaken flag of plagiarism, the post can simply be edited to add the appropriate self-attribution and be flagged for moderator attention.
