PlaceholdersEditableWithoutSettings setting from sitecore 6.5

From sitecore 6.5 (CMS 6.5.0 and DMS 2.0.0 rev. 110602 ) onwards,
if you go to the page editor and try to edit, it won't display any add button/placeholder if placeholder settings were not configured in layout details of the item (i.e. item -> presentation -> details)


<!--  WEB EDIT PLACEHOLDERS EDITABLE WITHOUT SETTINGS
      Indicates whether placeholders should be editable in the Page Editor if placeholder settings are not specified.
      Default value: false
-->
<setting name="WebEdit.PlaceholdersEditableWithoutSettings" value="false" />


if needs to use dynamic placeholders or need to edit a placeholder without setting placeholder settings prior, then set this setting to "true".