It really is unfortunate that Alamy sometimes cannot clearly explain what it means. In the blog post IPTC data was explicitly named as being where you ought not to put your personal contact details. Now, I know that most professional photographers do put their details there to prevent their images being orphaned. However, the point is, it really doesn't matter as far as images placed on Alamy matters, because they strip all the IPTC data out and replace them with Alamy's contact details. That didn't strike me until I downloaded a couple and checked the file info.
So what Alamy seems to be concerned about is stuff in the other, display fields - keywords, captions and description etc. Why couldn't the nice people in Alamy just have said that. My apologies to all for the fuss engendered.