Recently W3C has released its recommendations for MathML. Part of that recommendation was for keeping tags in lower case. The main rationale that I know of for doing this is that the page will compress better if more of it is in lower case. I do not find this as compelling a reason for making this a standard as that for ease of markup and page maintenance, besides uppercase has been standard practice so far and computers can easily manage both cases.
When I teach HTML I insist that my students type the tags in uppercase, so that it is clear when scanning a page which parts are markup and which are the actual content. I am not the only instructor to teach this, I have found a number of online sites and a number of reference books who also insist on such a markup style. For myself this comes from long experience in updating and fixing HTML pages. HTML editing programs can display markup in a different colour from markup, but not all authors will have access to this sort of software including blind and colour blind authors. I am afraid that W3C is planning on recommending the MathML format for all markup and I would like to see people urging them to reconsider.
Copyright © 1999 Katherine Phelps