How to display custom content when viewing node? I am using the Biblio module and I like the display mode (e.g. full, teaser).  I would like to tack on custom text and information when a user views the content below the display.  How do I append my own custom text in the current display?  When I go to "Manage Display", the custom fields are not shown.  It might be hard coded in the module.  What Drupal API call should I be looking for? Or better yet, I am perfectly willing to write my own module.  I just do not know where to start in adding my own additions to an existing display.

An example is the comment module.  When someone leaves a comment, then you can see the comment someone has written that is tied to the specific node and/or content type.  I am not talking about creating a user input form or input HTML field.
I resolved it by using hook_node_view() to append to the $node->content object.