Warning DOCTYPE Override in effect!

Hello,
 
the following direct input to the validator (with SVG 1.1 selected from 
Doctype list):
 
<?xml version="1.0" encoding="utf-8"?>
<svg version="1.1" ...
 
led to the warning
<quote>The DOCTYPE Declaration for "SVG 1.1" has been inserted at the start 
of the document, but even if no errors are shown below the document will 
not be Valid until you add the new DOCTYPE Declaration.</quote>
 
Context: I had just removed the DTD declaration after reading
[1] https://www.w3.org/TR/SVG11/intro.html#NamespaceAndDTDIdentifiers
<https://www.w3.org/TR/SVG11/intro.html#NamespaceAndDTDIdentifiers>
<quote>It is not recommended that a DOCTYPE declaration be included in SVG 
documents.</quote>
[2] https://www.w3.org/QA/2002/04/valid-dtd-list.html
<https://www.w3.org/QA/2002/04/valid-dtd-list.html>
<quote>Beyond the specificities of (X)HTML processing, Doctype declarations 
in XML languages are only useful to declare named entities and to 
facilitate the validation of documents based on DTDs. This means that in 
many XML languages, doctype declarations are not necessarily 
useful.</quote>
 
I guess from [2] that I need to declare a DTD for an svg file only if it 
also contains (X)HTML (my input was pure SVG).
If so, the validator may check for the presence of (X)HTML before emitting 
that warnimg.
 
Best regards
Rainald Koch