As discussed on: http://make.wordpress.org/docs/2013/04/09/adopt-a-codex-page/#comment-21173
This is a proposed new Codex article, splitting off Page Templates from the Pages article: http://codex.wordpress.org/Pages#Page_Templates
Most of the Pages#Page_Templates info is included here, but re-written somewhat. All the Examples are preserved, but given consistent formatting (eg, indents), and updated from Twenty Eleven theme structure to Twenty Thirteen.
Also added some examples of my own, which are more for dev purposes, but may be helpful: http://codex.wordpress.org/User:Hearvox/Custom_Page_Templates#Page_Template_Functions
Thanks so much for doing this!
Don't you mean "wp-content", not "wp-includes" in http://codex.wordpress.org/User:Hearvox/Custom_Page_Templates#File_Folders
Or did I miss a rearrangement of things? Converting2wp 15:07, 18 April 2013 (UTC)
I sure did mean "wp-content", good catch, corrected. and thanks, User:Hearvox