XS_NSFS_POSTFIX_FOR_MERGED_PART_MARK
Category in Advanced options dialog: Marking - parts
Use this advanced option to define the postfix in merged part marks. The postfix is visible for identical parts on both side of a main part. The default value is BS (both sides). Other possible values are NS (near side) and FS (far side).
This advanced option is model specific and the setting is saved in the options database.
In merging part marks, you may also find the following advanced options useful:
XS_MULTIPLIER_SEPARATOR_FOR_MERGED_PART_MARK
XS_NS_POSTFIX_FOR_MERGED_PART_MARK