User`s guide

LIBRARY
the library, RT–11 replaces those library modules. If the modules in the input
file do not exist in the library, RT–11 inserts them.
The following example updates the library OLDLIB.OBJ:
.LIBRARY OLDLIB FIRST/UPDATE,SECOND/UPDATE
Note:
The /UPDATE option must follow each file specification to which it applies.
You can use this option only with modules, not files.
162 RT–11 Command Descriptions