Element, Id Changed

Question

I am developing a web application with MVC 5. In a cshtml file I have the line "<p id="tcf" class="text-center" style="font-size:@viewfs%;overflow: hidden;">Conversations</p> ". When I publish the application the line changes to "<p d="tcf" class="text-center" style="font-size:@viewfs%;overflow: hidden;">Conversations</p>" and javascript GetElementById fails. What would cause this change of id="tcf" to d="tcf"?