HTTP Referrer. Is it reliable?
107534
How reliable is HTTP_REFERER?
17374
Better HTTPS support for Stack Exchange sites
29002
HTTP and HTTPS impacts on SEO
24082
Why does my browser think that https://1.1.1.1 is secure?
4558
Reference: mod_rewrite, URL rewriting and "pretty links" explained
76864
What is the best way to check if a URL exists in PHP?
113744
Server.Transfer Vs. Response.Redirect
17035
How can I prepend http to a url if it doesn't begin with http?
49036
Are drops in Google ranking common after switching to https?
55275
Does https encrypt URLs, too?
153795
Short way to link to http from https (and vice versa) using relative links
22095
How to prevent automatic redirection of 404 errors and "incorrect" URLs?
106659
URLConnection or HTTPClient : Which offers better functionality and more efficiency?
106624
Linking to a external Url - currently unsuccessful
34559
PHP Get Site URL Protocol - http vs https
84607
Is using only HTTPS bad in a SEO perspective?
36551
How does the referral system work?