diff --git a/docs/DataFlow.md b/docs/DataFlow.md
index c33f52751..a4431c841 100644
--- a/docs/DataFlow.md
+++ b/docs/DataFlow.md
@@ -16,3 +16,6 @@ Key
 | NLP Algorithms | Validated production ready algorithms run on identifiable free text data (e.g. Dose Reports, Structured Reports) and output results useful for cohort building into the relational database |
 | Relational Database | Only tags useful for cohort building that are easily (and reliably) anonymised (e.g. 5% of all tags) |
 | Cohort building | Only tags useful for cohort building and only study/series level (e.g. 4% of all tags) |
+| Researcher Zone (from CTP) | DICOM images with tags anonymised by CTP.  These include technical tags (some of which are
+ not loaded to Relational / used in cohort building), date tags, anonymised patient ID e.g. 12% of original tags|
+ | Researcher Zone (from NLP) | DICOM files containing full clinical reports (e.g. Dose Reports, Structured Reports). These reports would need to be be anonymised with a dedicated NLP tool as free text report redacting is not something CTP is set up to do.  A high proportion of the clinical report content would need to remain in these files for most free text research activities e.g. 98%|