[ENH] Alternative directory organization for raw, derived, and source data

src/02-common-principles.md

@@ -109,6 +109,29 @@ these data are to be included:
 1.  We RECOMMEND including the PDF print-out with the actual sequence parameters
     generated by the scanner in the `sourcedata` folder.
 
+Alternatively one can organize their data in the following way
+
+```Text
+my_dataset/
+  sourcedata/
+    ...
+  rawdata/
+    dataset_description.json
+    participants.tsv
+    sub-01/
+    sub-02/
+    ...
+  derivatives/
+    ...
+```
+
+In this example **only the `rawdata` subfolder needs to be BIDS compliant** 
+dataset. This specification does not prescribe anything about the contents of 
+`sourcedata` and `derivatives` folders in the above example - nor does it 
+prescribe the `sourcedata`, `derivatives`, or `rawdata` folder names. The above 
+example is just a convention that can be useful for organizing raw, source, and 
+derived data while maintaining BIDS compliancy of the raw data folder.
+
 ## The Inheritance Principle
 
 Any metadata file (`.json`, `.bvec`, `.tsv`, etc.) may be defined at any