@a2j 25 January 2022 more from that month

I've always thought that it was spelt sulphur or sulfur. But CAPTCHAs taught me a new spelling. "SULPHER". It smells fishy, but that is what the CAPTCHA wanted me to fill in. I googled it and realised there are some entries on some websites that spell it that way. I can't figure out if it is a typo or an official spelling! Or did the CAPTCHA maker make a typo?