The WMSCapabilitiesMime element is used as a subelement of the Globals element to specify an alternate MIME type for the WMS capabilities document. This document is returned in Express Server's GetCapabilities response. By default, the MIME type is application/vnd.ogc.wms_xml. For example, the following will force Express Server to return its capabilities document with the MIME type text/xml.
<Globals>
...
<WMSCababilitiesMime>text/xml</WMSCababilitiesMime>
...
</Globals>