MSIR.0422 ALTERNATES not allowed on SIRFIELD (subcmd) command because ERROR format already specified and records have been added to the file

This message indicates that a SIRFIELD 'subcmd' command was issued with the ALTERNATES clause, and the ERROR format had previously been set for the field. Since records have been added to the file, allowing new ALTERNATES could cause previous values matched by ERROR to now be matched by an alternate format, which might change the data, for example when you reorganize the file.

The command is rejected.