Each function string belongs to a function-string class, which groups function strings intended to be used with databases of a similar type or with similar requirements.
Replication Server assigns each database connection a function-string class according to the data server of the destination database.
Replication Server applies functions to the database using the function strings from its assigned function-string class. Function-string classes contain function strings for system functions and for any user-defined functions.
You can use a function-string class on multiple databases if the function strings can execute on all of the data servers. For example, a system with several databases managed by Adaptive Server can use rs_sqlserver_function_class for all the databases.
You can even use a single function-string class with non-ASE data servers, provided you use ECDA or the relevant ExpressConnect Option to access the various data servers.