Papers submitted for possible presentation at a conference and for publication in the conference proceedings are subjected to a double-blind, peer review process.
Papers are first reviewed by the conference chair. The conference chair may reject it out of hand either because it is not dealing with the subject matter for that conference or because it is manifestly of a low quality so that it cannot be considered at all. Papers that are found suitable are then sent to two experts in the field of the paper. Referees of a paper are unknown to each other.
Referees are asked to classify the paper as acceptable for presentation and publication, acceptable with amendments and improvements, or not acceptable.
Referees each return a peer-review of the paper to the conference chair. The role of the referees is advisory. Authors of the accepted papers then receive an acceptance letter.