Why do some query strings work even if parameters are not URL-encoded?

Question

Here\'s an example:

https://drive.google.com/viewerng/viewer?embedded=true&url=http://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_

Answer 1

This is from the relevant RFC, 1738:

https://www.ietf.org/rfc/rfc1738.txt

3.3. HTTP

The HTTP URL scheme is used to designate Internet resources
accessible using HTTP (HyperText Transfer Protocol).

The HTTP protocol is specified elsewhere. This specification only
describes the syntax of HTTP URLs.

An HTTP URL takes the form:

  http://:/?

where and are as described in Section 3.1. If : is omitted, the port defaults to 80. No user name or password is
allowed. is an HTTP selector, and is a query
string. The is optional, as is the and its
preceding "?". If neither nor is present, the "/" may also be omitted.

Within the and components, "/", ";", "?" are
reserved. The "/" character may be used within HTTP to designate a
hierarchical structure.

The special characters in "http://" only apply to the "protocol" specification at the start of the URL. It's optional in most browsers (implicitly "http://").

The first "?" separates the "path" from the "searchpart". Each "&" separates different arguments in the "searchpart".

Your browser should differentiate between ?embedded=true and &url=http://www.pdf995.com/samples/pdf.pdf.

'Hope that helps