It has appeared in encoded data strings within SEC Edgar filings , likely as part of an automated data transmission code.
In regional planning documents, it can refer to a Development Permit (DP) associated with a Riparian Areas Regulation (RAR) assessment report. dp.rar
If you are looking at a file on your computer, a file is a compressed archive. You will need a utility like WinRAR , 7-Zip , or The Unarchiver to open it and view the actual text or data inside. It has appeared in encoded data strings within