Hello everyone, I write for professional trade magazines in the video production niche. In 2010 I had an article published in a small Canadian magazine. Their writer's guidelines didn't mention anything about rights and neither did my correspondence with the editor. I'm now pitching the same topic to a (larger) U.S. magazine. I'm disclosing in my query that "it will be based on an article I published in 2010 but updated and at a higher technical level." Should I contact the Canadian editor or notify him of anything? Can I assume it was under first serial rights? We have a good working relationship and I'm having more articles published by him. Thanks!