The Semantic Web Interest Group is part of the W3C Semantic Web Activity. It is a general discussion forum for Semantic Web related technical, social, outreach, etc. issues. Note, however, that there is another mailing list (public-sweo-ig@w3.org, also with public archives) that is more specifically dedicated to outreach and educational issues around the Semantic Web.
Contributors to the list are considered to be members of the Interest Group, and should be familiar with the charter of the group, in particular it's commitment to a royalty free patent policy for W3C Semantic Web technologies.
The Semantic Web Interest Group provides an opportunity to share perspectives on Semantic Web technology and applications. W3C advises that information shared in the interest group through mailing list and meetings is publicly visible. W3C reminds participants to disclose, where known, the IPR status of information that they share in the Interest Group meetings and materials, in accordance with Section 6 of the W3C Patent Policy.
See the SW IG homepage for links to other W3C lists linked to this Interest Group.
Note: The group existed from 1999 to 2004 as the "RDF Interest Group". See www-rdf-interest@w3.org archives and the old RDF IG homepage. The Semantic Web Interest Group, now uses semantic-web@w3.org as it's home list.