Here in Switzerland
We call them 'gennaker' if it is a 'asymmetrical spinnaker'. Abbreviation would be 'genny'. <img src="http://www.catsailor.com/forums/images/graemlins/tongue.gif" alt="" />

A 'spinnaker' or 'spi' here is symmetrical, if not specified as an asymmetrical spinnaker.

Agree it is confusing! <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />