However, there are some useful shortcuts: if you are organizing your information through Prospero, theattributes you are likely to want to set on an object (COLLATION-ORDER, MENU-ITEM-DESCRIPTION, and OBJECT-INTERPRETATION) are in the APPLICATION namespace, which is the default for set_atr. You almost certainly want to just keep one instance of the attribute around, so set_atr defaults to using its replace option. If you want to delete the attribute entirely, use the -delete-all option.
If no attribute precedence is explicitly specified, set_atr selects what it believes the correct attribute precedences are using an adaptive mode: If a link is external, set_atr will set a a REPLACEMENT attribute on it. If a link is to an object stored under Prospero, set_atr will set an OBJECT attribute on the object and then cache the value of the OBJECT attribute with a CACHED value on the link itself. If set_atr can't modify the object itself, it will override the object's value of the attribute by putting a REPLACEMENT value on the link.