What on earth is a DCN and what’s it got to do with Reliability Screening?

If you’re looking at the fingerprint applicant request form and reading these words — “Personnel security screening applicant – A criminal record check with the Royal Canadian Mounted Police (RCMP) is required to process your personnel security screening request with the Government of Canada.
To complete this check, visit an RCMP-accredited third-party fingerprint service provider and have your fingerprints taken electronically and submitted to the RCMP” — you