Re: Which PHP-files are used to render a page?
@lupin3 – I don’t know any off the shelf function that prints the filename. Depending on your browser, tools like firebug on firefox and developer tools on Safari may help you.
Location of the files really depends which part of your theme you mean: the main blog / news ones or the social network specific ones such as profile, groups, etc.
For the blog specific pages – this page gives you an overview of all the WP files: https://codex.wordpress.org/Theme_Development
I don’t know what documentation is still around on 1.1.3 theme files. However, most of the files were typically in fairly explanatory-named subfolders of your member theme (e.g. in folders such as friends, members, wire, activity, profile)
