adding script/HTML code to page

adding script/HTML code to page

Hello again guys,
I have run into this a few times now where I want to add some HTML code or, <script> to my page but, the way you have the editing set up, there is not script editing "allowed" and, when I go to add the HTML code in the settings/themes/edit HTML/CSS I always get an "error" saying "missing markups" missing [caption container] [content container] etc.

How are we supposed to design our web sites how we want them if we are limited in this way?

Thanks for your attention to these items.

AE