The rs_default_fs system variable allows you to perform the following tasks:
Extend function strings with replication-definition scope to include additional commands (such as those for auditing or tracking)
Customize rs_update and rs_delete function strings and still be able to use the replicate minimal columns option in your replication definitions
Function strings containing the rs_default_fs system variable may only be applied on Adaptive Servers or data servers that accept Adaptive Server syntax. Otherwise, errors will occur.
Refer to Chapter 3, “Replication Server Commands,” in the Replication Server Reference Manual for a complete list of function string system variables.