Detached signature of non-sibling elements (?)

Hi.
Altough XMLDSig [1] is quite old, stable and well-known, I havent been able
to understand (maybe a translation/missunderstanding issue) the detached
signatures properly.
According to [2]:
"*The signature is over content external to the Signature element, and can
be identified via a URI or transform. Consequently, the signature is
"detached" from the content it signs.*"
Ok. Detached elements...
"*This definition typically applies to separate data objects, but it also
includes the instance where the Signature and data object reside within the
same XML document but are sibling elements.*"
Ok. Signature and object in the same XML doc and siblings.
As stated in [3] (I't seems the standard doesnt distinguish between
internal/external)
"the signature and data can be in separate files or in the same XML file as
sibling elements"
Shall I understand the "internally detached" *unique valid signature* is
where signature and data are brothers (or sisters) [have the same parent]?
*Is the following example a valid detached signature? *
*<root>*
*    <my-data>*
*        <node Id="n"></node>*
*    <my-data>*
*    <my-sign> *
*        <signature ref="n"></signature>    </my-sign>*
*</root>*
Thanks a lot for your help
Regards
[1] https://www.w3.org/TR/xmldsig-core/
[2] https://www.w3.org/TR/xmldsig-core/#def-SignatureDetached
[3] https://msdn.microsoft.com/en-us/library/ms759193%28v=vs.85%29.aspx