diff --git a/.gitignore b/.gitignore
index 86b9124..711a2e1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,5 @@ Data
 env
 __pycache__
 .vscode
+dicom_anonymizer.egg-info
+dist
\ No newline at end of file
diff --git a/README.md b/README.md
index 5d59a25..b11c143 100644
--- a/README.md
+++ b/README.md
@@ -94,6 +94,17 @@ Example 2: We just want to change the study date from 20080701 to 20080000, then
 python anonymizer.py InputFilePath OutputFilePath -t '(0x0008, 0x0020)' 'regexp' '0701$' '0000'
 ```
 
+### Using custom rules to anonymize DICOMDIR files
+
+DICOMDIR files can have a `(0x0004, 0x1220)  Directory Record Sequence` tag that can contain patient information.  
+However, this tag is not part of the standard tag to anonymize set. In order to make dicom-anonymizer anonymize it, you have to instruct it explicitly:
+
+```python
+python anonymizer.py InputFilePath OutputFilePath -t '(0x0004, 0x1220)' replace
+```
+
+> It is better to regenerate DICOMDIR files after anonymizing the original DICOM files. Anonymize DICOMDIRs only if you have no other solution
+
 
 ## Custom rules with dictionary file