*FIXR
r11, r12, r13, r14
r21, r22, r23, r24
....
r11: r*8: min x-coordinate
r12: r*8: max x-coordinate
r13: r*8: min y-coordinate
r14: r*8: max y-coordinate
This card is used in conjunction with *AUTM, or *STLF to define the rectangular fixtures on the bottom of the substrate. All nodes within the defined rectangles are fixed in all 3 axes. The following figure illustrates the option.
Positioning of a rectangular constraint
Best Practices: Use *FIxR if practical, to avoid overconstraining the part.