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I will, tell me please I am not a professional on reddit, did I flair this post there ? : https://www.reddit.com/r/steemit/comments/7h99mo/steem_dollar_sbd_hits_25_or_000023585_btc_35_in_2/?ref=share&ref_source=link (I changed the flair after posting this)

I changed today a flair to DOLPHIN because I love dolphins from my chilhood. ☺

Will every my post there will be with a flair DOLPHIN or just the new ones ?

You have changed your username flair to Dolphin. You can still flair your posts with another flair. Just go to the link you posted, and it should be an option to flair it right below the main post / above the comment section.

I didn't find that option, there is just sort by, can you make a screenshot please ?

Hmm, I can't really screenshot it, because it should only be visible to the person who posted the link. I could try to submit a post on the subreddit later today to see if I can find it and screenshot it :)

ok, I'll wait thanks