The Web Feature Service (WFS) Reader enables FME to retrieve geographic information from a WFS-compliant server.
WFS is an OpenGIS® Implementation Specification. The WFS specification defines the request and response rules for the retrieval of geographic information using Hypertext Transfer Protocol (HTTP).
The WFS reader adheres to versions 1.0.0, 1.1.0, and 2.0.0 of this specification, which can be found at the OpenGIS Consortium website www.opengis.org.
Reader Overview
At minimum, all compliant WFS servers are required to encode their geodata using the OpenGIS Geography Markup Language (GML). The WFS reader invokes FME’s GML reader to process this data.
Messages that are logged during a WFS read session are produced by both the GML reader and the WFS reader. All requests that originate from the WFS reader are prepended with a <WFS> string.
Troubleshooting WFS Errors
https://knowledge.safe.com/articles/19452/troubleshooting-wfs-errors.html