The CRC Handbook of Chemistry and Physics, a frequently used reference work published by CRC Press.
"The student consulted CRC to verify the atomic weight of carbon before writing their lab report."
In plain English: A CRC is a special code that checks if data has been changed during transmission to make sure it arrived correctly.
"The crc in this network protocol ensures that data packets arrive without errors."
Initialism of Chemical Rubber Company. (a former US-American manufacturer of chemical laboratory equipment, now the publishing company CRC Press.)
"The CRC Handbook of Chemistry and Physics is a well-known reference published by the publisher formerly known as CRC."