I took a look at the requests sent to the DLNA server by foobar2000 and MC. foobar2000 sends a Browse request without filtering and MC sends a Search request with filtering. Here are the requests in full:
---- request sent from foobar2000 to DLNA server ----
<?xml version="1.0" encoding="UTF-8"?>
<s:Envelope s:encodingStyle="
http://schemas.xmlsoap.org/soap/encoding/" xmlns:s="
http://schemas.xmlsoap.org/soap/envelope/">
<s:Body>
<u:Browse xmlns:u="urn:schemas-upnp-org:service:ContentDirectory:1">
<ObjectID>1$13$744776851</ObjectID>
<BrowseFlag>BrowseDirectChildren</BrowseFlag>
<Filter>*</Filter>
<StartingIndex>0</StartingIndex>
<RequestedCount>50</RequestedCount>
<SortCriteria></SortCriteria>
</u:Browse>
</s:Body>
</s:Envelope>
---- request sent from MC to DLNA server ----
<?xml version="1.0" encoding="UTF-8" ?>
<s:Envelope xmlns:s="
http://schemas.xmlsoap.org/soap/envelope/" s:encodingStyle="
http://schemas.xmlsoap.org/soap/encoding/" xmlns:xsi="
http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="
http://www.w3.org/2001/XMLSchema">
<s:Body>
<u:Search xmlns:u="urn:schemas-upnp-org:service:ContentDirectory:1">
<ContainerID>0</ContainerID>
<SearchCriteria>(upnp:class derivedfrom "object.item.audioItem")</SearchCriteria>
<Filter>dc:title,res,res@protection,res@duration,res@sampleFrequency,res@bitsPerSample,res@bitrate,res@nrAudioChannels,upnp:artist,upnp:artist@role,upnp:genre,upnp:album,upnp:albumArtURI</Filter>
<StartingIndex>0</StartingIndex>
<RequestedCount>1000</RequestedCount>
<SortCriteria>+dc:title</SortCriteria>
</u:Search>
</s:Body>
</s:Envelope>