Hi, new user...
Been going through the forums and faqs and haven't been able to find the answer.

I want to be able to drop in html and php code when creating pages eg.) in Sections.

For example, if I want to drop in a link to another page or call in an image. I know I can do this with straight html
eg) <a href="http://localhost/site/modules/sections/index.php?op=viewarticle&artid=2"> link</a>

But, I want this to work on localhost as well as the production server.
eg) <a href="<php echo XOOPS_URL . ('/modules/sections/index.php?op=viewarticle&artid=2'); ?>">link</a>

Unfortunately, it doesn't render the php code.

Any ideas ? Suggestions?

The theme file is a html file .
So you cannot add php code .
You can use xoop template tags.

You can use the tag <{$xoops_url}> for XOOPS url
<{$xoops_theme}> for theme folder..

Try to edit the default theme file.You will get all these codes ...

Does anyone know where these are defined?

I'd like to add some of my own, and realize that I need to include it in the smarty definitions, or something similar...

Don't know too much PHP, but know enough to be dangerous!

Thanks in advance...

Most, maybe all, of the XOOPS-wide ones are set in header.php and include/common.php. Look for calls to $xoopsTpl->assign and $xoopsTpl->append.