Error message tags

Error message tags are WBSP placeholders for various parts of an error message. They are not intended to be used on the ordinary WBSP pages nor in normal circumstances, but in error template file (defined by WB_ErrFile variable and sent to client when error occurs). Their purpose is to format and/or hide some of the error details. Also, when output type (Content-type) is not text/html they can be used to generate proper error report (e.g. XML, XHTML, WML, RTF, etc.)