[GRASSLIST:2992] problem with ppm file

[Anand Mohan]

hi 
  I am working with grass and grasslinks.I need some help about ppm file.In ppm file 
MAPLP = ${MAPLP-$HOME/paint.ppm}

here paint.ppm represents what.ie is it dynamically created file or what.help me.

Thank & Regards
Anand Mohan G