diff --git a/src/icartt/dataset.py b/src/icartt/dataset.py
index df445c09b54483ba10b8f3bba62f587ea50f65e3..86065c4bad864aa067f4eed0cdbf187bf1ff2eb6 100644
--- a/src/icartt/dataset.py
+++ b/src/icartt/dataset.py
@@ -926,6 +926,8 @@ class Dataset:
             else:
                 self.inputFhandle = f
 
+        # TODO should we add a filename characters check, as we have it for the variable names?
+
             self.readHeader(splitChar)
             if loadData:
                 self.endDefineMode()