What are the other methods to restrict a webpage from the search index?
 

we can use noindex meta tag. Read more here www. robotstxt. org/meta.html

here is some other tips :

Use a robots.txt robots exclusion file
use “noindex” page meta tags :
Use Password protect sensitive content
use Nofollow: tell search engines not to spider some or all links on a page
Don’t link to pages you want to keep out of search engines
Use X-Robots-Tag in your http headers

Goodluck