Yes, in GetCapabilities and DescribeFeatureType as stated in the GML Simple Feature profile documentation:
GetCapabilities:
The following XML fragment shows how a WFS may advertise in its
capabilities document that it can generate schemas that comply with
this profile:
1. <ows:Operation name="DescribeFeatureType">
2. <ows:DCP>
3. <ows:HTTP>
4. <ows:Post xlink:href="http://www.BlueOx.org/wfs"/>
5. </ows:HTTP>
6. </ows:DCP>
7. <ows:Parameter name="outputFormat">
8. <ows:Value>text/xml; subType=gml/3.1.1</ows:Value>
9. <ows:Value>text/xml; subType=gml/3.1.1/sfgml</Value>
10. </ows:Parameter>
11. </ows:Operation>
Line 9 indicates that this WFS can generate a GML application schema that conforms to this profile.
DescribeFeatureType XML-encoded request:
The following example XML fragment shows a DescribeFeatureType request
indicating that the response should conform to this profile:
<DescribeFeatureType outputFormat="text/xml; subType=gml/3.1.1/sfgml"/>
DescribeFeatureType KVP-encode request:
The following example URL shows a DescribeFeatureType request
indicating that the response should conform to this profile:
http://www.BlueOx.org/wfs/wfs.cgi?service=WFS&version=1.1.0&request=DescribeFeatureType&outputFormat=text/xml;+subType=gml/3.1.1/sfgml