GSASII: Z Parameter

Hi all, I am using GSASII for refinement. After uploading powder data and phase data, you can begin refining the standard UVW and XY parameters under the "Instrument Parameter" tab. These are the familiar parameters seen in GSAS, but there is an additional Z parameter located just under the X an

Si Zero-Background Holder Pattern subtraction in GSASII

Hi all, I am performing refinement in GSASII on a pattern that was taken with a Si zero-background holder. I am unable to figure out how to subtract/ignore the peaks associated with the zero-background holder. Any advice is appreciated, thanks in advance. Best, Caelin ++