diff --git a/README.md b/README.md
index b5ee35c..9511f6c 100644
--- a/README.md
+++ b/README.md
@@ -90,8 +90,16 @@ In Item Properties:
 
 ### Linking the Items
 
-In Items that declare this `processing` extension, it is recommended to add one or more [Links](https://github.com/radiantearth/stac-spec/blob/master/item-spec/item-spec.md#relation-types) with `derived_from` or `via` relationships to the eventual source metadata & data used in the processing.
+In Items that declare this processing extension, it is recommended to add one or more
+[Links](https://github.com/radiantearth/stac-spec/blob/master/item-spec/item-spec.md#relation-types) that document lineage,
+using `derived_from` to point to upstream inputs the data product was derived from,
+and `via` to point to alternative representations used in the creation of the Item (e.g., an authoritative metadata record used for conversion).
 They could be used to trace back the processing history of the dataset.
+Note that `derived_from` can point back to different types of metadata, which are distinguished through the media type (`type`):
+- `application/geo+json` → STAC Item
+- `application/json` → STAC Catalog/Collection; for other JSON metadata, use `application/json; profile=my-other-metadata-standard`.
+- `text/html` → website
+- Any other media type (e.g. `application/xml`) → other metadata (e.g. XML)
 
 ### Suggested Processing Levels