Setting expiration date in a content type policy
1. This will work if you have SharePoint Standard or Enterprise
edition. Open your site in a browser.
2. Select "Site Actions > Site Settings".
3. Click "Go to top level site settings". Of course, you don't
see this link if you are already on the top level site.
4. Click "Site content types" under "Galleries".
5. Locate the content type that you want to use for setting the
policy on. Click the link of the content type.
6. Click "Information management policy settings" under
Fig 1: Settings
7. Select "Define a policy..." option and click OK.
Fig 2: Define a policy
8. Check "Enable Expiration" checkbox. Select "Created" or
"Modified" in the item's properties and select days, months or
years from the last drop down in the row. Enter a number in the
middle text box. Now select action. You can choose the default
action "Delete" or you can start a workflow and do custom
actions. Click OK to save the settings.
Fig 3: Setting Expiration
Hope this will help someone. It is straight forward but I have
seen users asking this question "How to set expiration policy on
a content type".