The following use of character entities & aborts in ConTeXt. That is of course because the # is seen as a parameter. Changing this to &\#xxx; or &\letterhash xxx; typesets & as is, but that is not the intention, because an ampersand should appear. So, how do I proceed here?

Minimal example:
% test character entity failure.
\startxmlsetups demo:entity
\startxmlsetups demo:entity:root
\blank Start test:\crlf
root: <amp> = "&amp;"\crlf
root: <number> = "&\letterhash 038;”\crlf % &\#038; produces the same
End test\blank
{\bf Testing use of character entities}\blank
These should produce the same result: \type{&amp;} and \type{&#038;}\blank