The Manaslu Circuit Trek takes you through a trail that has been declared as a restricted area by the Nepal Government. So, it is compulsory to obtain a Manaslu Restricted Area Permit (MRAP), Manaslu Conservation Area Permit (MCAP), and Annapurna Conservation Area Permit (ACAP) to trek through the restricted areas for several reasons including conservation efforts, regulation of tourism, and safety of the trekkers.
S. S. International Journal of Next-Generation Networks (IJNGN), volume 4 of IFIP Advances in Information and Communication Technology, page 21 - 27. (March 2012)