Dear tobster,
Please open "tag.aspx", you can find the following method, it enumerates the elements of tag.config,
foreach(XmlElement xe in doc.DocumentElement.SelectNodes("add"))
{
string tab=xe.GetAttribute("tab");
if(IsTagPattern(tagName,xe.GetAttribute("pattern")))
{
bool isactive=(index==0&&(tabName==null||tabName==""))||(string.Compare(tab,tabName,true)==0);
if(isactive)
{
tabcontrol=xe.GetAttribute("control");
tabtext=xe.GetAttribute("text");
}
%>
................
Thank you for asking