DEI stands for Diversity, Equity, and Inclusion. Here is NYSED's initiative on DEI.
SEL means Social/Emotional Learning. Here are NYSED SEL Learning Benchmarks.
The RBERN is funded by a contract from the New York State Education Department to provide technical assistance at no charge to school districts with English Language Learners in the counties of Albany, Clinton, Columbia, Essex, Franklin, Fulton, Greene, Hamilton, Herkimer, Lewis, Montgomery, Otsego, Rensselaer, Saratoga, Schenectady, Schoharie, St. Lawrence, Warren and Washington.