Drupal's default page title follows one of two patterns:
The Page Title module lets you change these defaults in two ways. First, you can adjust the patterns below using the placeholders given. This will change the way the default page titles are created. Second, on enabled forms (curently node, term & user editing forms) you have the option of specifying a title that is different to the title of the item. This field only appears if the Show Field box is checked for the item. If a value is provided it will be used to generate the [current-page:page-title] placeholder however if it is left blank the [current-page:page-title] token will inherit the item's own title.
The [current:page-title] token will default to the value returned from drupal_get_title if there is no value specified or no available page title field.
Certain types of page title pattern have access to special tokens which others do not, depending on their scope. All patterns have access to the Global scope. Content type patterns have access to the Node tokens, vocabulary patterns have access to the Taxonomy tokens and finally the user patterns have access to the User tokens.