Maximum percentage of physical memory that can be consumed by data structures to support /dev/pts entries. A system running a 64-bit kernel consumes 176 bytes per /dev/pts entry. A system running a 32-bit kernel consumes 112 bytes per /dev/pts entry.
0 to 100
When you want to either restrict or increase the number of users that can log in to the system. A value of zero means that no remote users can log in to the system.