material safety data sheet, n an informational form detailing the chemical and physical properties, hazards, and ways of safely handling a toxic chemical.
BRB means be right back. It is one of the most commonly used acronyms in online chat and texting. It communicates that the person is leaving for a moment, but will be back shortly.
SSB (single sideband) is a mode where the carrier and one sideband of the AM mode has been suppressed. Whether using USB (upper sideband) or LSB (lower sideband) more of the transmitter's signal is focused in the sideband used as compared to AM.