Switching between HTTP and HTTPS

Question:

Following statements are there in my Apache2 virtual hosts section

Redirect /host/directory/folder/login.php https://servername/host/directory/folder/login.php
Redirect /host/directory/folder/register.php https://servername/host/directory/folder/register.php

How to return to http (not https) when the above 2 pages are not involved?

Answer:

In HTTP VH:
RewriteRule /.../login.php https://.../login.php [R]
RewriteRule /.../register.php https://.../register.php [R]

In HTTPS VH:
RewriteRule /.../login.php - [S=2]
RewriteRule /.../register.php - [S=1]
RewriteRule ^/(.*) http://servername/$1 [R]

In the HTTPS VH, if you get login.php or register.php you don't rewrite it (the "-"), then you skip the next 2 or 1 RewriteRules ( [S=2], [S=1]) - that is, you skip over the general purpose rewrite back to HTTP. So login.php or register.php get served from HTTPS and everything else goes back to HTTP.