The result attribute defines the assigned name for this filter primitive. If supplied, then graphics that result from processing this filter primitive can be referenced by an in attribute on a subsequent filter primitive within the same <filter> element. If no value is provided, the output will only be available for re-use as the implicit input into the next filter primitive if that filter primitive provides no value for its in attribute.
You can use this attribute with the following SVG elements:
This value is a <custom-ident> and defines the name for the filter primitive. It is only meaningful within a given <filter> element and thus has only local scope. It is legal for the same <filter-primitive-reference> to appear multiple times within the same <filter> element. When referenced, this value will use the closest preceding filter primitive with the given result.