Add docs note about authenticated queries

docs/eso/eso.rst

@@ -103,6 +103,33 @@ interaction with the ESO archive.
     INFO: Downloading file 1/1 https://dataportal.eso.org/dataPortal/file/ADP.2023-03-02T01:01:24.355
     ERROR: Access denied to https://dataportal.eso.org/dataPortal/file/ADP.2023-03-02T01:01:24.355
 
+
+.. The doctest-skip directive is not working for pytest within the note directive, thus
+   we leave the snippet below as a code-block
+
+.. note::
+
+    Even after logging with `~astroquery.eso.EsoClass.login()`, TAP queries are not authenticated by default. To issue
+    authenticated queries, the keyword argument ``authenticated`` must be set to `True` explicitly in the query functions.
+    For example:
+
+    .. code-block:: python
+
+       eso = Eso()
+       eso.ROW_LIMIT = None
+       eso.login(username="ICONDOR")
+
+       # Some files are missing without `authenticated=True`
+       files_tbl = eso.query_instrument("nirps")
+
+       # Get all files to which the authenticated user has access
+       files_tbl = eso.query_instrument("nirps", authenticated=True)
+
+    Review your queries carefully and update them accordingly to ensure you are retrieving
+    all your expected results. If you don't stricly need to run an authenticated query, use
+    the default ``authenticated=False``, since it will retrieve your results much faster.
+
+
 Automatic password
 ------------------