LPub Preferences. You can also create your own file if you wish.
A typical element in the standard file is for example a 32x32 baseplate. This would be too large to display at full scale in the PLI. A smaller scale is specified in the PLI Controlfile.
Another example part is a Technice Plate 2 x 4 With Holes. Unless you use it in combination with a normal 2 x 4 plate it could be easily mistaken by a normal plate.
This part is not standard in the pli.mpd file so if you wish to use it you should add it in MLCad and slightly tilt it over the X-axis.
Alternatively you can paste this line of code in pli.mpd:
1 16 180 0 0 1 0 0 0 0.970296 -0.241922 0 0.241922 0.970296 3709b.dat