Indirectly Related Files
When files are indirectly related to each other, no direct connection is visible between the file boxes. The relation is established via a third file box with a direct relation to these files.
Referenced files
These are files that are directly as well as indirectly referenced. For example, if Schema A has an Include statement that references Schema B, and Schema B has an Include statement that references Schema C, then (i) Schema B is directly referenced by Schema A, (ii) Schema C is directly referenced by Schema B, and (iii) Schema C is indirectly referenced by Schema A (since Schema A references Schema B, which in turn references Schema C).
If a schema that is directly referenced by an XML file references another schema (e.g. Schema B is imported by Schema A), this schema (Schema B in our example) is said to be indirectly referenced by the XML file.
Any schemas and XSLT files that are included or imported in files directly referenced by XSLT stylesheets are said to be indirectly referenced by these stylesheets. So, in the example below, Catalog.xsd is indirectly referenced by Stylesheet.xslt because it is imported in Import.xslt which is included in Stylesheet.xslt.
WSDL files can contain (inline) schemas or and these (inline) schemas can include, import, or redefine other schemas. Any schema that is included, imported, or redefined in such a schema (like Schemas Import, D, and Catalog in the example below), is indirectly referenced by the WSDL file.
In the case of an .mfd file, in addition to the directly referenced source and target schemas, any schema that the source schema references or the target schema is referenced by (Schema Z in our example) is considered to be referenced by the .mfd file.
Referencing files
Files that are directly as well as indirectly referencing the selected file.
All related
This option applies to both referenced and referencing files with a direct as well as indirect reference.