diff --git a/api_koreader/xpointer_cfi_utils.py b/api_koreader/xpointer_cfi_utils.py
index 37b0c06173c77f9b0d3be539796fdc3f9b709004..89625e53278ae3c8661f27e25772d423640d9762 100644
--- a/api_koreader/xpointer_cfi_utils.py
+++ b/api_koreader/xpointer_cfi_utils.py
@@ -245,6 +245,9 @@ def inner_cfi_to_kr(xml: Tag, inner_cfi_ref: str, basedir: str, files_index: dic
     element_regex = r"(\d+)(?:\[(.*)\])?"
     pointer_regex = r"(\d+)(?:\[(.*)\])!"
 
+    # TODO make sure simple ranges are stripped
+    # e.g. epubcfi(/6/4[chap01ref]!/4[body01]/10[para05],/2/1:1,/3:4)
+
     matches_text = re.match(text_regex, curr_ref_item)
     matches_element = re.match(element_regex, curr_ref_item)
     matches_pointer = re.match(pointer_regex, curr_ref_item)