Are there any specific guidelines in using CAPITAL LETTERS for HTML/PHP tags rather than lowercase? Is it okay (in terms of search engine optimization) to have both capital letters tags and lowercase letter tags?


If it doesn't matter, does someone have a recommendation or tool to go through hundreds of PHP/HTML pages and change all appropriate tags to lowercase or uppercase? Can DreamWeaver or Notepad++ or TextPad do such a thing (without screwing up any other text/source, etc)