Just realised there is an error is my basic, basic code, the last tag is incorrect.
NOTE last tag is now the correct </part> and not the wrong <part> tag, it makes a difference!

The full fixed basic code is....

<part>
<name>PARENT_POLY</name>
<animation>
<parameter>
<code>
(A:LIGHT STROBE,bool)
if{ 100 } els{ 0 }
</code>
<lag>60</lag>
</parameter>
</animation>
</part>