What are the template name for "Post new topic" and "Post A reply" and where are they normally stored?

Is the same templates used for all forums?
Can these be customized to add links and info messages?

The link below shows an example of some preliminary changes made but these changes have not been made to the original template.

http://www.portone.com/aghatch1/misc/new_post_rev3.html

http://www.portone.com/aghatch1/misc/post_reply_rev1.html

How can i implent these changes into the real template?