I'm aware that there are many ways that people have of spelling "croquil" which is just a squashed form of the words "crow quill". I use the spelling that I myself jotted onto the envelope I keep my croquil nibs in and I like to think that, at the time and place I was introduced to the finest of the families of inking nibs, "croquil" was the accepted spelling. And I refuse to take the spelling of a word (and all of its variations) that drops a lovely letter like 'w' seriously.