'send_software_release_number' specifies if the HTTP server will tel the client what release of Pliant it's running on.
The default is true.
The release number may be used to check if the HTTP server contains a known security hole, so you may want to suppress it, also the extra security it brings is really thin since changing the option will not remove the hole.

An example:

pliant module /pliant/protocol/http/server.pli command 'http_server port 8080 send_software_release_number false name "PARANO"'