How to exclude a list or library from SharePoint Search

Scenario:
Do you ever wonder why Workflow Task list items or Master Page Gallery documents never show up in SharePoint search ?

Or

May be you have SharePoint lists or libraries storing some data for internal use and you don’t want them to show up in search results…

Reason:
SharePoint allow to set you list/library level attribute to be included/excluded with-in the Search results.

Steps:
1. Navigate to any existing list.
2. Click on Settings --> List Settings
3. Click on Advances Settings
4. Check the last section "Search"