View the source.

&

The "&amp" below should be styled as the one above:

&ampFOOBAR;

The following should be styled as entities:

©
&copy
©
&COPY

The ones below should not be styled as entities:

&FOOBAR;
&Chi
&Dagger
&COpy;

(It's OK to style the erroneous ones (all except & © and ©) as being in error, though.)